When was the Citizenship Act passed?

1955

The correct answer is Option 2 - 1955

The Citizenship Act of India was passed in 1955. The exact date is 30th December, 1955.
Amendments:

The Act has been amended several times since 1955, with some significant changes including:
The Assam Accord (1985): This addressed the issue of illegal immigration in Assam.
Citizenship Amendment Act (2019): This introduced a new pathway to citizenship for immigrants belonging to specific religious minorities from Pakistan, Afghanistan, and Bangladesh.

Here's a breakdown of the CAA's implementation timeline:
December 2019: Passed by Parliament.
January 10, 2020: Originally announced to come into force.
March 11, 2024: The CAA rules, necessary for implementation, were finally notified by the government.