International Customs Day is observed on 26 January every year because on that date in 1953

The correct answer is A, 15 March. World Consumer Rights Day takes its date from 15 March 1962, when United States President John F. Kennedy sent a message to Congress setting out the rights of the consumer, the first time a head of government did so; the consumer movement began observing the day in 1983. Option B is wrong because 24 December is National Consumer Rights Day in India, tied to the assent given to the Consumer Protection Act, 1986. Option C is wrong because 5 December is the International Day of Banks, declared by the United Nations General Assembly in 2019. Option D is wrong because 15 May is the International Day of Families and has nothing to do with consumer protection. Remember the pair: the world day in March, the Indian day in December.

The correct answer is A, the Consumer Protection Act received the assent of the President. The Consumer Protection Act, 1986 was given assent on 24 December 1986, and the Department of Consumer Affairs observes that date every year as National Consumer Rights Day with a theme. Option B is wrong because the observance marks the law, not the opening of any particular district forum, and consumer courts were set up after the Act came into operation. Option C is wrong because the Consumer Protection Act, 2019, which replaced the 1986 Act and created the Central Consumer Protection Authority, came into force in 2020; the date of the observance did not move with it. Option D is wrong because the Bureau of Indian Standards came from a separate Act and is a standards body, not a consumer grievance law.

The correct answer is B, 24 July. Income tax was introduced in India on 24 July 1860 by Sir James Wilson, the first finance member of the Viceroy council, to repair the finances of the government after the revolt of 1857, and the Income Tax Department has observed the day since 2010, the hundred and fiftieth year of the tax. Option A is wrong because 1 April is the first day of the financial year and the day the Reserve Bank of India began operations in 1935, which makes it a tempting distractor. Option C is wrong because 31 July is only the usual last date for filing a return, not the day of the tax. Option D is wrong because 1 July is GST Day, the day the goods and services tax came into force in 2017.

The correct answer is C, 2017. The goods and services tax came into force on 1 July 2017, and the day is observed every year as GST Day. The legal foundation was the Constitution (One Hundred and First Amendment) Act, 2016, which inserted Article 246A and created the GST Council under Article 279A, but the tax itself started a year later. Option A is wrong because 2014 is the year the amendment Bill was introduced in Parliament, not the year the tax began. Option B is wrong because 2016 is the year of the constitutional amendment, which is the commonest trap in this question. Option D is wrong because 2019 brought later changes in rates and in the return system, not the launch. Keep the pair in mind: amendment in 2016, tax from 2017.

The correct answer is B, P. C. Mahalanobis. Prasanta Chandra Mahalanobis was born on 29 June 1893, founded the Indian Statistical Institute, gave the country its large-scale sample survey system and the statistical distance known by his name, and shaped the Second Five Year Plan. The Government declared his birth anniversary as National Statistics Day in 2007. Option A is wrong because C. R. Rao, though a statistician of the first rank and a student of Mahalanobis, is not the figure the day honours. Option C is wrong because V. K. R. V. Rao was an economist who founded the Delhi School of Economics and the Institute for Social and Economic Change. Option D is wrong because D. R. Gadgil was an economist associated with the Gokhale Institute and with the formula for plan assistance to states.