In the Reflection of a Light Beam from a Flat

In the reflection of a light beam from a flat mirror, the angle between the incident and reflected beams relative to the perpendicular to the surface of the mirror is:

A) equal to the angle between the incident beam and the perpendicular.
B) equal to 1/2 the angle between the incident beam and the perpendicular.
C) always a right angle, or 90°.
D) twice the angle between incident beam and the perpendicular.