Which statement correctly describes the path of one of the three principal rays used to locate an image formed by a concave spherical mirror?
a) A ray that leaves the top of the object traveling through the center of curvature reflects back parallel to the principal axis.
b) A ray that leaves the top of the object traveling parallel to the principal axis reflects through the focal point on the same side of the mirror.
c) A ray that leaves the top of the object traveling parallel to the principal axis reflects through a point located halfway between the focal point and the center of curvature.
d) A ray that leaves the top of the object traveling toward the focal point reflects back parallel to the principal axis on the opposite side of the mirror.