Match List-I with List-II and select the correct answer:

List I	List II
a. Bank rate policy	1. Involving the shortening of the currency of bills eligible for rediscount.
b. Credit rationing	2. Involving the purchase and sale of securities in the open market.
c. Vanable reserve system	3. Involving the alteration of discount rate.
d. Open market operation	4. Involving the variation of the minimum reserves.

A. a-1, b-4, c-2, d-3

B. a-2, b-1, c-3, d-4

C. a-4, b-2, c-1, d-3

D. a-3, b-1, c-4, d-2

Answer: Option D