The most populous district in Mizoram is:

Aizawl
Lunglei
Champhai
Kolasib

The correct answer is Aizawl. Aizawl is the capital and most populous district of Mizoram, India. It is located in the central part of the state and has a population of over 250,000 people. The district is known for its beautiful scenery and its unique culture.

Lunglei is the second most populous district in Mizoram. It is located in the southern part of the state and has a population of over 150,000 people. The district is known for its tea plantations and its beautiful waterfalls.

Champhai is the third most populous district in Mizoram. It is located in the eastern part of the state and has a population of over 100,000 people. The district is known for its tribal culture and its beautiful forests.

Kolasib is the fourth most populous district in Mizoram. It is located in the northern part of the state and has a population of over 50,000 people. The district is known for its rice cultivation and its beautiful hills.