The Anti-Defection Bill was passed when Rajiv Gandhi was the Prime Minister of India. The Anti-Defection Bill is a legislative act in India that aims to prevent political leaders from switching parties or voting against their party`s decisions. The bill was introduced to ensure stability in the political system and discourage opportunistic politicians from changing party affiliations for personal gain.

Option 1, Indira Gandhi, is not the correct answer. Indira Gandhi served as the Prime Minister of India during the periods 1966-1977 and 1980-1984, which was before the Anti-Defection Bill was passed.

Option 3, V.P. Singh, is also not the correct answer. V.P. Singh was the Prime Minister of India from 1989 to 1990. This was after the passage of the Anti-Defection Bill.

Option 4, Deve Gowda, is not the correct answer either. Deve Gowda served as the Prime Minister of India from 1996 to 1997, which was also after the Anti-Defection Bill was passed.

Based on the options provided, the correct answer is option 2, Rajiv Gandhi, who was the Prime Minister of India when the Anti-Defection Bill