$$\frac{6^{\frac{4}{3}}. (24)^{\frac{2}{5}}}{9^{\frac{1}{4}}. 12^{\frac{1}{2}}} = 3^a2^b$$, then $$a + b =$$

A

$$\frac{34}{15}$$

B

$$\frac{29}{15}$$

C

$$\frac{31}{15}$$

D

$$\frac{22}{15}$$