Find the C.I. on a sum of Rs.1600 for 9 months at 20% per annum, interest being compounded quarterly?

Find the C.I. on a sum of Rs.1600 for 9 months at 20% per annum, interest being compounded quarterly?

A. Rs.17684
B. Rs.1684
C. Rs.2522
D. Rs.3408
Explanation:
A = 1600(21/20)3 = 2522