The Critical Angle for a Substance in Air Is Measured

Multiple Choice

The critical angle for a substance in air is measured at 53.7°.If light enters this substance from air at 45.0° with the normal,at what angle with the normal will it continue to travel?

A) 34.7°
B) 45.0°
C) 53.7°
D) It will not continue,but will be totally reflected.