Answer:
I think it's Dhaka.
Step-by-step explanation:
I did some research and found that Dhaka, also spelled Dacca, city and capital of Bangladesh. It is located just north of the Buriganga River, a channel of the Dhaleswari. Also, it is one of the most populous cities in the world.
Also, Sylhet is a city in eastern Bangladesh, not the capital, and Jamalpur is a town in India in the state of Bihar.
Hope I helped :)