A Beam of Light in Air Is Incident at an Angle

Multiple Choice

A beam of light in air is incident at an angle of 15° to the surface of a rectangular block of clear plastic (n = 1.46) .The light beam first passes through the block and re-emerges from the opposite side into air at what angle to the normal to that surface?

A) 22°
B) 10°
C) 15°
D) 18°
E) ​0.39°