# Two vertices of a triangle are $(3.-5)$ and $(-7,4)$ .If its centroid is $(2,-1)$ then its third vertex is ___________
$\begin{array}{1 1}(A) \;(-10,2) \\(B)\;(10,-2) \\(C)\;(-10,-2) \\(D)\;(10,2) \end{array}$