What is meant by Repo rate?

A    When a bank is in need of cash it can it can discount bills of exchange and avail loan facilities from Reserve Bank of India

B    When a bank has excess cash, they buy securities from RBI against cash on the condition that they resell the securities to RBI on a pre fixed day and price

C    It is rate at which RBI allows temporary loan facilities to commercial banks against government securities on the condition that the bank will repurchase the securities within a short period

D    It is a rate which is offered by banks to their most valued customers or prime customers