Why is bank necessary? In short?​

Bank as in river? Or bank as in where you store your money?

Banks play an important role in the economy for offering a service for people wishing to save. Banks also play an important role in offering finance to businesses who wish to invest and expand. These loans and business investment are important for enabling economic growth.

A)30b)29c)28d)31hope this .

Bis the answer because it deals with social insurance.