In a Complex Design Experiment Researchers Found That Younger and Older

Multiple Choice

In a complex design experiment researchers found that younger and older people performed equally well on a memory task when they were tested in the morning,but the younger people performed better than the older people when they were tested in the afternoon.The different effect of age at the two times of day represents a(n)

A) main effect.
B) correlated effect.
C) interaction effect.
D) comparison effect.