Question

question 33
most large telescopes are reflectors rather than refractors because
reflectors have better angular resolution than refractors of the same size
lenses cannot observe all wavelengths of visible light
reflectors have greater magnification than any of the refractors
a large mirror is easier to polish & is more easily supported than a large lens

Explanation:

Reflectors use mirrors. Large mirrors are easier to polish as they only need one - side polishing compared to lenses which need both sides polished. Also, large mirrors can be supported from the back, while large lenses are difficult to support without sagging due to their weight and the need to be transparent throughout.

Answer:

D. a large mirror is easier to polish & is more easily supported than a large lens