How can india's cities be so large when most people live in rural areas

It's hard to say about India,I think its because of the economy, i think their economy isn't all that great and the people have to live in rural areas because that's the cheapest place they could afford. Plus in some of the large cities they have buildings for jobs, hospitals, schools and groceries stores. 

Thats what i think.
Hope this helped :)
Have a great day 

Ibelieve the answer is c also i'm in k12 too