If a Person Wants to Build a Telescope Having the LEAST

Multiple Choice

If a person wants to build a telescope having the LEAST possible amount of chromatic aberration, one should use

A) a front lens that has been coated with a special material to reduce refraction.
B) a front lens that is composed of two closely spaced lenses made of different kinds of glass.
C) the thinnest front lens that one can obtain.
D) mirrors instead of lenses.