Assertion(A):- Northern Plains is a densely populated physiographic division of India. Reason:- With a rich soil cover combined with adequate water supply and favourable climate it is agriculturally productive part of India.

a. Both A and R are true and R is the correct explanation of A.
b. Both A and R are true and R is not the correct explanation of A.
c. A is true, but R is false.
d. A is false, but R is true.

a. Both A and R are true and R is the correct explanation of A.

Explanation:

Because that's the correct reason

More to know:

Nothern plains are made up by Ganga, Brahmaputra and Indus rivers.

It is mainly made of alluvial soil, which is highly fertile.

if you are on the computer you can not take a picture but you can upload one but i am not sure about phones but i'm pretty sure it's the but to upload one just click the paper clip looking thing/ link thingy thing and upload a pic

because the early people found out about it.