In a Laboratory Experiment, Bill and Jason Find That When

In a laboratory experiment, Bill and Jason find that when children are induced to perceive their parents as having eyes in the back of their heads (i.e., that the parents are always "watching them") , the children are less likely to do drugs in the future. In a follow-up study, children who do drugs reported less agreement with the statement "my parents seem to have eyes in the back of their head." In this example, the relationship between drug use and parental monitoring is most likely:

A) noncausal covariation
B) spurious correlation
C) bidirectional causation
D) unidirectional causation