At which Conference of the Parties did India announce its target of net zero emissions by 2070?

The correct answer is C, one tonne of carbon dioxide equivalent. The tonne is the standard trading unit in every carbon market, compliance or voluntary, and it is written as 1 tCO2e. The word equivalent matters: gases other than carbon dioxide are converted into carbon dioxide terms using their global warming potential, so a much smaller quantity of methane or nitrous oxide can earn one credit. A is wrong because a kilogram is far too small to be a market unit; no registry issues credits in kilograms. B is wrong for the same reason, and a hundred kilograms is simply a tenth of the real unit, a figure offered to catch a candidate who half-remembers the tonne. D is wrong because a thousand tonnes is the scale of a whole small project's annual saving, not of a single credit; a project of that size would be issued a thousand separate credits, which is exactly how buyers are able to purchase them in small lots.

The correct answer is B, the Kyoto Protocol. Adopted in 1997 at COP3 in Japan and in force from 2005, it set binding emission targets for developed countries and gave them three flexible mechanisms to meet them; the Clean Development Mechanism, under Article 12, let a developed country fund an emission-reduction project in a developing country and claim the saving as Certified Emission Reductions. A is wrong because the Montreal Protocol of 1987 deals with ozone-depleting substances such as chlorofluorocarbons and has no emissions-trading machinery. C is wrong because the Cartagena Protocol, under the Convention on Biological Diversity, governs the transboundary movement of living modified organisms. D is wrong because the Nagoya Protocol, also under that Convention, covers access to genetic resources and the fair sharing of benefits from their use. Only the Kyoto Protocol belongs to the climate treaty family that creates carbon credits.

The correct answer is C, Certified Emission Reductions, abbreviated CER, each equal to one tonne of carbon dioxide equivalent and issued only after an accredited third party verifies the saving. India hosted a very large number of such projects and was among the world's biggest sellers of CERs. A is wrong because Emission Reduction Units arise from Joint Implementation, where one developed country funds a project in another developed country, not in a developing one. B is wrong because Assigned Amount Units are the emission allowances handed to developed countries themselves under Article 17, traded directly between governments rather than earned by a project. D is wrong because Renewable Energy Certificates are an Indian domestic instrument that lets an obliged buyer meet its renewable purchase obligation without owning a generating plant; they measure electricity from renewable sources, not avoided greenhouse gas, and have no standing under the Kyoto Protocol.

The correct answer is B, Article 6. It holds all the market machinery of the Paris Agreement: Article 6.2 lets two countries cooperate bilaterally and transfer Internationally Transferred Mitigation Outcomes with a corresponding adjustment so the same tonne is not counted twice, Article 6.4 establishes a centralised crediting mechanism supervised by a United Nations body as the successor to the Clean Development Mechanism, and Article 6.8 covers non-market approaches such as finance and technology transfer. A is wrong because Article 2 states the purpose of the agreement, including holding the temperature rise well below two degrees Celsius. C is wrong because Article 9 deals with climate finance from developed to developing countries. D is wrong because Article 14 provides for the global stocktake, the periodic review of collective progress. Note the coincidence candidates stumble on: Article 6 of the Kyoto Protocol is Joint Implementation, a different thing.

The correct answer is C, the Energy Conservation Act, 2001. The Energy Conservation (Amendment) Act, 2022 inserted the power for the Central Government to specify a Carbon Credit Trading Scheme, which is why the market sits with the Ministry of Power and its Bureau of Energy Efficiency rather than with the environment ministry. A is wrong, and is the commonest trap, because the Environment (Protection) Act, 1986 is an umbrella law for standards, notifications and eco-sensitive zones, not for tradable credits. B is wrong because the Electricity Act, 2003 governs generation, transmission, distribution and tariff regulation; renewable purchase obligations sit there, but carbon credits do not. D is wrong because the Air Act, 1981 created the pollution control boards and deals with local air pollutants such as particulate matter and sulphur dioxide, which are regulated by consent and standards rather than by trading.