Which among the following images show the correct path of a light ray while passing through a rectangular glass slab?

The correct option is B

As the glass slab is an optically denser medium, the light bends towards the normal when entering the glass slab from air. When the light leaves out of the glass slab, it is going from denser to rarer medium so it bends away from the normal and therefore it appears to be slightly shifted from its original track. In rectangular glass slab, the direction of emerging light is same as that of incident light.

The dotted line shows the path of light which it would have taken if there was no glass slab in its path where as the strong line shows the path taken by light after refraction from glass slab.