What will be the electric field at point P. Assume (r >> a)

Question

 

$\begin{array}{1 1} (A)\;\frac{kqa^2}{r^4}\\ (B)\;\frac{6kqa^2}{r^2} \\ (C)\; \frac{6kqa^2}{r^4} \\ (D)\;\frac{6kqa^2}{r^4} \end{array}$