The electric field in a region is given by $\;\overrightarrow{E}=\alpha \hat{i}+\beta \hat{j}\;.$ Here $\;\alpha\; and \; \beta\;$ are constants . The net flux through a square are of side l parallel to y - z plane

Question

$(a)\;\alpha\;l^2\qquad(b)\;\beta\;l^2\qquad(c)\;(\alpha+\beta)\;l^2\qquad(d)\;\large\frac{\alpha+\beta}{2}\;l^2$