The rods, which number over 100 million, can only be activated by a certain range of wavelengths, but they do not pass any color information to the brain. In other words, they note differences in shades of grey (from black to white) and are responsible for a person's ability to see in dim light. Cones, which number around 6 million, give us color vision. Cones come in three different kinds: 64%% of cones are sensitive to long wavelengths of visible light (toward the red end of the spectrum), 32%% are sensitive to medium wavelengths, and the remaining 2%% are sensitive to short wavelengths (toward the blue end of the spectrum). Colors are differentiated on the basis of the extent to which visible light stimulates each kind of cone. Do rods have their peak sensitivity at a higher or lower frequency than cones?
a) Higher
b) Lower