Dr Clinton's Experiment Finds That His 20-Year-Old Subjects, Tested Under

Multiple Choice

Dr. Clinton's experiment finds that his 20-year-old subjects, tested under cool temperatures, show little anger, whereas his 15-year-old subjects, tested under hot conditions, show significantly greater anger. In this experiment the two variables of age and temperature are

A) matched.
B) nonlinear.
C) randomized.
D) reliable.
E) confounded.