Consider a cube of side length '$a$' centered at the origin. It is enclosed by three fixed point charges: $(-q)$ at $(0, -a/4, 0)$,$(+3q)$ at $(0, 0, 0)$,and $(-q)$ at $(0, a/4, 0)$. Choose the correct option.

• A
  The net electric flux crossing the plane $x = +a/2$ is equal to the net flux crossing the plane $x = -a/2$.
• B
  The net electric flux crossing the plane $y = +a/2$ is greater than the net flux crossing the plane $y = -a/2$.
• C
  The net electric flux crossing the entire region is $\varepsilon_0$.
• D
  The net electric flux crossing the plane $z = a/2$ is equal to the net electric flux crossing the plane $x = +a/2$.