If the simple interest at the same interest rate on ₹500 for 4 years and ₹700 for 2 years, combined together, is ₹280, then what is the rate of interest?

A

$$9\frac{3}{17}\%$$

B

$$6\frac{5}{17}\%$$

C

$$8\frac{4}{17}\%$$

D

$$7\frac{3}{17}\%$$