\( C_1 \) and \( C_2 \) are two hollow concentric cubes enclosing charges \( 2Q \) and \( 3Q \) respectively as shown in figure. The ratio of electric flux passing through \( C_1 \) and \( C_2 \) is:
\( 2:5 \)
\( 3:2 \)
\( 2:3 \)
\( 5:2 \)