A Light Ray Passes from Air Through a Thin Plastic $\degree$

Multiple Choice

A light ray passes from air through a thin plastic slab (n = 1.3) with parallel sides.If the ray in air makes an angle of 45 $\degree$ with the normal after leaving the slab,what is the angle of incidence for the ray in air as it impinges upon the other side of the slab?

A) 33 $\degree$
B) 45 $\degree$
C) 67 $\degree$
D) 58.5 $\degree$