The correct answer is B. 25th June, 1975 to 21st March, 1977.
The Internal Emergency was a period of 21 months from 25 June 1975 to 21 March 1977 when the Indian government under Prime Minister Indira Gandhi was given emergency powers by President Fakhruddin Ali Ahmed. The Emergency was controversial and led to widespread arrests and suppression of civil liberties.
The Emergency was declared after a series of political setbacks for Gandhi’s government, including the defeat of her Congress Party in the 1974 Gujarat Legislative Assembly
election and the Allahabad High Court’s judgment in the Raj Narain case, which found her guilty of electoral malpractice. Gandhi claimed that the Emergency was necessary to maintain law and order and to deal with the threat of internal subversion.Under the Emergency, the government was given sweeping powers to arrest and detain people without trial, to censor the press, and to
suspend civil liberties. Thousands of people were arrested, including political opponents, journalists, and activists. The press was censored and the opposition was silenced.The Emergency was lifted on 21 March 1977, after Gandhi’s Congress Party was defeated in the 1977 general election. The Emergency is widely considered to be a dark chapter in Indian history.
The other options are incorrect because they do not correspond to the actual dates of the Emergency.