Reflecting telescopes are popular because they're

A. more powerful than a refracting telescope.

B. smaller than a refracting telescope.

C. easier to build than a refracting telescope.

D. more durable than a refracting telescope.

C. easier to build than a refracting telescope

Big mirrors used in reflecting telescopes are easier and cheaper to make than big lenses which would cost more because of the quality of glass required to make refracting telescopes