The Sunset Law was associated with ________  .

The correct option/answer is Zamindari System/Permanent Settlement.

The Sunset Law (also known as the Sunset Clause) was a crucial regulatory feature of the Permanent Settlement (Zamindari System) introduced by the British Governor-General Lord Cornwallis in 1793 in Bengal, Bihar, and Odisha.
Under this law, if a Zamindar (landlord) failed to pay the fixed land revenue to the East Indian Company's treasury by sunset on the specified date of payment, their estate/Zamindari was immediately confiscated by the British administration and auctioned off to recover the dues.
This strict enforcement mechanism was designed to ensure timely revenue collection for the colonial government, but it placed immense pressure on the Zamindars, leading to the sale of many traditional estates to new urban merchants and speculators.