Find equation of the line perpendicular to the line $x-7y+5=0$ and having $x$ intercept 3.

Question

$\begin{array}{1 1}(A)\;7x-y=21 \\(B)\; 7x+y=-21 \\(C)\; y-7x+21=0 \\(D)\;7x+y=21 \end{array}$