已知 $A,B$ 均为集合 $U=\left\{1,3,5,7,9\right\}$ 的子集，且 $A\cap B=\left\{3\right\}$ ,( $C_{U}B$ $\cap A$ = $\left\{9\right\}$ ,则 $A$ =

A．

$\left\{1,3\right\}$

B．

$\left\{3,7,9\right\}$

C．

$\left\{3,5,9\right\}$

D．

$\left\{3,9\right\}$