A and B started a business with B's investment 2.5 times that of A. Ratio of time period of the investment of A and B was 3 : 1 and the total investment made by both of them was Rs.28000. If the annual profit earned was Rs.2500 less than A's investments, the difference between their annual profit is (in rupees)

A

400

B

500

C

650

D

800