If $$a = \sqrt{9} - \sqrt{7}, b = \sqrt{7} - \sqrt{5}, C = \sqrt{11} - \sqrt{9}$$ and $$d = \sqrt{5} - \sqrt{3}$$ then

A

$$b > c > a$$

B

$$a > c > b$$

C

$$d > a > b$$

D

$$d > b > c$$