What is not an advantage that a reflecting telescope has over a refracting telescope?
D) refracting telescopes are usually lighter than reflecting ones. The question is stated weirdly, it would've been better to ask what advantage a refracting telescope has over a reflecting one.
e) is not an advantage. It is also untrue. All the others may or may not be an advantage, as Nyx points out.
That's such a poorly worded test question. a) Yes, both can be supported on the back. However, that center of gravity makes it easier on the bearings. b) A reflector can be in a smaller dome, since it has folded optics. However, the question needs to state the sizes of each telescope in order to keep the comparisons equal. c) Nearly the same as b. It's a function of focal length of the scope. d) Again, that's a function telescope size. But also the material it is constructed out of. e) Isn't correct. Refractors have more chromatic aberration.
Isn't it obvious?