Which of the following is the best explanation of why it is difficult to discriminate the color of an object at night?
A. Cones come in three types, each sensitive to different wavelengths of light.
B. At night, dilation of pupils stimulates the retina, where more rods are located rather than cones.
C. The foveae are densely packed with cones.
D. As many as 100 cones may converge on one ganglion cell.