Which is the largest city in the world by population?

a) New Delhi

b) Dhaka

c) Karachi

d) Tokyo 

The capital of Japan, Tokyo is by far the largest city in the world by population. It has a population of about 37.2 million, which makes it the largest city. Indian capital, New Delhi is the second largest city in the world with a population of 32.9 million. Chinese city Shanghai is third largest city with a population of 29.2 million.