National Sports Day is celebrated in India on 29 August, the birth anniversary of:

The correct answer is A, Swami Vivekananda. Swami Vivekananda was born on 12 January 1863 at Kolkata, and the Government of India declared his birthday National Youth Day in 1984, first observed in 1985, because his writings and his address at the Parliament of Religions at Chicago in 1893 are held up as a model for young Indians. Option B is wrong because Raja Ram Mohan Roy, the social reformer who worked against sati, is remembered on a different date. Option C is wrong because Bal Gangadhar Tilak, who said that freedom was his birthright, was born on 23 July. Option D is wrong because Subhas Chandra Bose was born on 23 January, now observed as Parakram Diwas, a date that is deliberately placed in the options because it falls in the same month.

The correct answer is B, Dr Sarvepalli Radhakrishnan. Dr Radhakrishnan, philosopher, professor and the second President of India, was born on 5 September 1888. When students wished to celebrate his birthday in 1962, he suggested that the day be kept for teachers instead, and it has been Teachers' Day ever since. Option A is wrong because Dr Rajendra Prasad was the first President of India and his birthday is not linked to this observance. Option C is wrong because Maulana Abul Kalam Azad, independent India's first Education Minister, is honoured on 11 November as National Education Day, a closely related fact that is often set as the distractor. Option D is wrong because Dr Zakir Husain, an educationist who became President, is not the person behind this day. Note also that World Teachers' Day falls on 5 October.

The correct answer is B, Jawaharlal Nehru. Jawaharlal Nehru, the first Prime Minister of India, was born on 14 November 1889, and because of his affection for children, who called him Chacha Nehru, the date was adopted as Children's Day or Bal Diwas. Option A is wrong because Mahatma Gandhi was born on 2 October, observed as Gandhi Jayanti and as the International Day of Non-Violence. Option C is wrong because Indira Gandhi, the first woman Prime Minister of India, was born on 19 November, a date close enough to be used as a trap in the options. Option D is wrong because Sardar Vallabhbhai Patel was born on 31 October, now observed as Rashtriya Ekta Diwas or National Unity Day. Keep the November pair separate: 14 November for Nehru, 19 November for Indira Gandhi.

The correct answer is A, Sir M Visvesvaraya. Sir Mokshagundam Visvesvaraya was born on 15 September 1861 in Mysore state, and he is remembered for the Krishna Raja Sagara dam, the block system of irrigation gates and his years as Diwan of Mysore. He was awarded the Bharat Ratna in 1955. Option B is wrong because E Sreedharan, known as the Metro Man for his work on the Konkan Railway and the Delhi Metro, has no day named after him. Option C is wrong because A P J Abdul Kalam, the aerospace scientist and President, is remembered through his birthday on 15 October, observed as World Students' Day. Option D is wrong because Satish Dhawan led the Indian space programme and gave his name to the launch centre at Sriharikota rather than to a national day.

The correct answer is B, the announcement of the Raman effect. On 28 February 1928 the physicist C V Raman announced his discovery that light changes its wavelength when it is scattered by molecules, an effect that carries his name, and for which he received the Nobel Prize in Physics in 1930, the first Nobel Prize in science won by an Indian. The day has been observed since 1987. Option A is wrong because Aryabhata, India's first satellite, was launched in April 1975. Option C is wrong because the first nuclear test at Pokhran took place in May 1974 and the later tests in May 1998, marked by National Technology Day on 11 May. Option D is wrong because the founding of the space agency is not tied to this date. Note that this day marks a discovery, not a birthday.