A non-conducting spherical shell of radius $$R$$ surrounds a point charge $$q$$. The electric flux through a cap of the shell of half angle $$\theta$$ is

A

$$\frac{2\pi q\theta}{\varepsilon_0}$$.

B

$$\frac{q}{2\varepsilon_0}(1 - \cos\theta)$$.

C

$$\frac{q(2\theta)}{4\pi\varepsilon_0}$$.

D

$$\frac{q\theta}{2\pi\varepsilon_0}$$.