In One Study, 8 Volunteers Reduced Their Sleep by 30

In one study, 8 volunteers reduced their sleep by 30 minutes per night until they did not want to reduce it further.A major finding was that

A) 4 managed to reduce their sleep to 5 hours per night.
B) 2 managed to reduce their sleep to 4.5 hours per night.
C) the volunteers began to experience significant daytime sleepiness once they had reduced their sleep to 6 hours or less per night.
D) the volunteers were still sleeping between 7 and 18 hours less per week when they were tested 1 year later.
E) all of the above