Professor Sokolov Conducted an Experiment and Found That Younger People

Multiple Choice

Professor Sokolov conducted an experiment and found that younger people had significantly poorer sleep quality than older people. Based on the results, she can conclude that

A) sleep quality is related to age.
B) the sleep quality of any individual person can be reliably predicted by her or his age.
C) there is a causal relationship between participant age and sleep quality.
D) sleep quality declines with age.