After Telling Your Friends About the Role of Light in the Sleep-Wake

Multiple Choice

After telling your friends about the role of light in the sleep-wake cycle,one of them asks about blind people.You mention:

A) that nearly all blind people have serious problems with their sleep-wake cycle
B) all blind people must use auditory cues of time passage
C) the pathway for vision and for circadian rhythms are separate
D) blindness causes profound disturbances in sleeping that must be treated with hormone injections