A charged particle $q$ is placed at the centre $O$ of cube of length $L \;(ABCDEFGH)$. Another same charge $q$ is placed at a distance $L$ from $O$. Then the electric flux through $ABCD$ is : <br>

Question

( A ) $q/4 \pi \varepsilon_0L$
( B ) $q/3 \pi \varepsilon_0L$
( C ) $q/2 \pi \varepsilon_0L$
( D ) zero