The vertices of a triangle are $(1,k),(4,-3)$ and $(-9,7)$ and its area is 15 sq.units , then the value of k is

Question

$\begin{array}{1 1}(A) \;3\;or\;\large\frac{-21}{13} \\(B)\;-3\;or\;\large\frac{-21}{13} \\(C)\;-3\;or\;\large\frac{21}{13} \\(D)\;3\;or\;\large\frac{21}{13} \end{array}$