The electric potential at a point $\;(x , y)\;$ in the x- y plane is given by $\;V=-k\;x\;y\;$. The field intensity at a distance r in this plane , from the origin is proportional to

Question

$(a)\;r^2\qquad(b)\;r\qquad(c)\;\large\frac{1}{r}\qquad(d)\;\large\frac{1}{r^2}$