Given sets $A = \{ 1,3,5,7 \} , B = \{ 2,3,4,5 \}$, then $A \cap B =$\\ A. $\{ 3 \}$\\ B. $\{ 5 \}$\\ C. $\{ 3,5 \}$\\ D. $\{ 1,2,3,4,5,7 \}$