After Reviewing the Research Literature on Nightly Sleep Reduction and Trying

After reviewing the research literature on nightly sleep reduction and trying it himself,one of the authors of your text concluded that

A) most people need at least 8 hours of sleep per night.
B) many people can reduce their sleep to about 5.5 hours per night with no serious adverse effects other than daytime sleepiness when they are sedentary.
C) there is no need to sleep, and there are no negative consequences of sleep reduction.
D) sleep is primarily recuperative, and we should always get as much sleep as we can, especially if a doctor tells us to.
E) all people should sleep 5.5 hours per night.