A common tangent to $9x^2-16y^2=144$ and $x^2+y^2=9$ is

Question

$\begin{array}{1 1}(A)\;y=\frac{3}{\sqrt 7} x +\frac{15}{\sqrt 7} \\(B)\;y= 3 \sqrt {\frac{2}{7}} x+ \frac{15}{\sqrt 7} \\(C)\;y=2 \sqrt {\frac{3}{7}} x +15 \sqrt 7 \\(D)\;\text{none of these } \end{array}$