State the direction of the incident ray which after reflection from a spherical mirror retraces its path. Give a reason to your answer.
Options:
A) Parallel to the principal axis, because it will reflect back on the same path
B) At the focal point, because it will reflect back along the same path
C) At the center of curvature, because it will reflect back along the same path
D) At an angle to the principal axis, because it depends on the angle of incidence