A certain sum amoums to ₹13200 after 4 years and to ₹16400 after 8 years at the same rate per cent p.a. at simple interest. The simple interest (in ₹) on the same sum at 10% p.a. for $$3\frac{1}{5}$$ years will be:

A

4000

B

3200

C

2500

D

3500