The most populous district in Manipur is:

Imphal West
Imphal East
Thoubal
Bishnupur

The correct answer is Imphal West.

Imphal West is the most populous district in Manipur, with a population of 463,190 as of 2011. It is the administrative headquarters of the state and is home to the capital city of Imphal. The district is located in the central part of the state and is bordered by Imphal East district to the north, Thoubal district to the east, Bishnupur district to the south, and Senapati district to the west.

Imphal West is a diverse district with a mix of ethnic groups, including Meitei, Naga, Kuki, and Chin. The main language spoken in the district is Meiteilon. The district is also home to a number of religious groups, including Hinduism, Christianity, and Islam.

Imphal West is a major economic hub in Manipur. The district is home to a number of industries, including textiles, food processing, and handicrafts. The district is also a major agricultural center, with rice, maize, and sugarcane being the main crops.

Imphal West is a popular tourist destination. The district is home to a number of historical and cultural sites, including the Imphal Palace, the Kangla Fort, and the Shri Govindajee Temple. The district is also home to a number of natural attractions, including the Loktak Lake and the Keibul Lamjao National Park.