Constitution Day is observed in India on 26 November because on that day in 1949 the Constituent Assembly did which of the following?

The correct answer is B, Jawaharlal Nehru. India's first Prime Minister was born on 14 November 1889, and because of his known fondness for children, who called him Chacha Nehru, his birthday was adopted as Children's Day after his death in 1964.

Option A, Dr. Rajendra Prasad, the first President of India, was born on 3 December, a date now marked as the International Day of Persons with Disabilities rather than as any anniversary of his. Option C, Dr. S. Radhakrishnan, was born on 5 September, which India observes as Teachers' Day, and swapping Teachers' Day with Children's Day is the commonest error in this pair. Option D, Maulana Abul Kalam Azad, was born on 11 November, observed as National Education Day, so his date falls in the same month and only three days earlier, which makes him the sharpest distractor here. The United Nations separately observes World Children's Day on 20 November.

The correct answer is B, 11 November. The date is the birth anniversary of Maulana Abul Kalam Azad, born in 1888, who was independent India's first Minister of Education and the moving spirit behind the founding of the University Grants Commission and the Indian Institutes of Technology. The Ministry of Human Resource Development began observing the day in 2008.

Option A, 5 September, is Teachers' Day, the birth anniversary of Dr. S. Radhakrishnan, and it belongs to a different month altogether. Option C, 14 November, is Children's Day, the birth anniversary of Jawaharlal Nehru, and its nearness to 11 November is what makes it a trap. Option D, 26 November, is Constitution Day and also National Milk Day. Fixing the three November dates in order, 11 for education, 14 for children and 26 for the Constitution, keeps them apart in the hall.

The correct answer is B, Verghese Kurien. Born on 26 November 1921, Kurien is called the Father of the White Revolution in India. He built the Amul cooperative at Anand in Gujarat and led Operation Flood, the programme that made India the largest producer of milk in the world, and the day has been observed since 2014.

Option A, M. S. Swaminathan, is associated with the Green Revolution in wheat and rice, not with milk, and is remembered as the Father of the Green Revolution in India. Option C, Tribhuvandas Patel, founded the Kaira district milk cooperative that grew into Amul and brought Kurien into the movement, so his name belongs to the same story but not to this date. Option D, Norman Borlaug, was the American agronomist whose high yielding wheat varieties began the Green Revolution worldwide, and he won the Nobel Peace Prize in 1970. Only Kurien's birthday gives National Milk Day.

The correct answer is A, 1 December. World AIDS Day was first observed in 1988 and was the first global health day of its kind, set aside to spread awareness of HIV and AIDS and to remember those who have died of the disease. The same date in India is the Raising Day of the Border Security Force, which was raised on 1 December 1965.

Option B, 7 December, is Armed Forces Flag Day in India and International Civil Aviation Day. Option C, 10 December, is Human Rights Day, marking the Universal Declaration of Human Rights of 1948, and it is also the day the Nobel Prizes are presented. Option D, 2 December, is National Pollution Control Day in India, observed in memory of the Bhopal gas tragedy of 1984, and its nearness to 1 December makes it the most likely wrong pick. December's first ten days carry four separate observances, so they are best learnt as a block.

The correct answer is B, the Bhopal gas tragedy. On the night of 2 and 3 December 1984 methyl isocyanate gas leaked from a pesticide plant in Bhopal and killed thousands of people, in what remains the worst industrial disaster in India. The day is used to remember the victims and to press the case for industrial safety and for the enforcement of the pollution control laws.

Option A, the Chernobyl nuclear accident, happened in April 1986 in Ukraine, then part of the Soviet Union, and is marked by the International Day of Remembrance of the Chernobyl Disaster on 26 April. Option C, the Kyoto Protocol, was adopted in December 1997 and came into force in 2005, and it has no commemorative day of this kind. Option D, the Stockholm Conference of 1972, gave rise to World Environment Day on 5 June, a different observance altogether. Only the Bhopal disaster explains 2 December.