What would be the difference between the simple interest and the compound interest on a sum of the money at the end of four years? I. The rate of interest is 5 p.c.p.a. II. The sum fetches a total of Rs. 2000 as simple interest at the end of 8 years. III. The difference between the simple interest and the compound interest at the end of 2 years is Rs. 12.50. (a) II only (b) III only (c) II or III only (d) All I, II and III are required. (e) None of these