The accompanying figure shows the absorption spectrum for chlorophyll a and the action spectrum for photosynthesis. Which of the following statements best explains the low rate of photosynthesis at 550 nm?

A) Green and yellow wavelengths inhibit the absorption of red and blue wavelengths.
B) Oxygen given off during photosynthesis interferes with the absorption of light.
C) Other photosynthetic pigments absorb light in addition to chlorophyll a.
D) Chlorophyll a does not absorb 550 nm light well.