Answer:
The answer is A. The Indo-Gangetic Plain.
Step-by-step explanation:
The Indo-Gangetic Plain is a region located between northern and eastern India, Pakistan, Bangladesh and Nepal. It has a total population of 900 million people, being one of the most populated regions in the world. Its total population makes up for 1/8 of the world population. It is so highly populated mostly due to the fertile grounds.