A Cassegrain Reflecting Telescope Is Constructed Using A

A Cassegrain reflecting telescope is constructed using a:

A) concave primary mirror followed by a smaller convex secondary mirror that reflects light back through a hole in the primary mirror.
B) curved primary mirror followed by a series of both plane and curved mirrors that channel the light to a remote location that is fixed with respect to Earth.
C) concave primary mirror and concave secondary mirror that reflects light back through a hole in the primary mirror.
D) concave primary mirror and a flat, diagonal secondary mirror mounted at a 45° angle to the telescope axis.