Question

why are plants generally green?
a the pigment chlorophyll absorbs green light waves.
b the pigment chlorophyll reflects green light waves.
c chlorophyll a and b, required for photosynthesis, is green.
d within the visible spectrum, plants prefer green wavelengths.

Explanation:

Plants appear green because chlorophyll, the main pigment involved in photosynthesis, absorbs light in the red and blue - violet regions of the visible spectrum and reflects green light. Option A is incorrect because chlorophyll does not absorb green light. Option C is a bit of a misstatement; it's the reflection of green light by chlorophyll that makes plants green, not just the fact that chlorophyll is green (the green color is due to reflection). Option D is incorrect as plants don't "prefer" wavelengths in the sense of a choice; it's a physical property of chlorophyll's light - absorption and reflection.

Answer:

B. The pigment chlorophyll reflects green light waves.