4. A certain sum is deposited for 4 years at a rate of 10% per annum on compound interest compounded annually. The difference between the interest at the end of 2 years and that at the end of 4 years is Rs.5,082. Find the sum (in Rs.). (A) 20,000 (C) 50,820 (B) 25,500 (D) 10,164​