Net flux through closed surface S is

Question

$\begin{array}{1 1} (a)\;\phi = \int \hat E \times \overrightarrow{ds} \\ (b)\;\phi = \int \hat E . \overrightarrow{ds}\\ (c)\;\phi = \large\frac{E}{4\pi \in_0} \\(d)\;\phi =4 \pi \in_0 E \end{array}$