A cone of base radius R and height h is located in a uniform electric field rightarrow{E}$\;\over\;$ parallel to its base. The electric flux entering the cone is :

Question

$(a)\;\large\frac{1}{2} \;\normalsize Ehr \qquad(b)\; \normalsize Ehr\qquad(c)\;2\normalsize Ehr\qquad(d)\;4\normalsize Ehr$