$$C_1$$ 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

A

2 : 5

B

5 : 2

C

2 : 3

D

3 : 2