Pete Wanted to See Whether Caffeine Intake Increased a Subject's

Pete wanted to see whether caffeine intake increased a subject's arousal state. He randomly assigned 100 high school seniors to an experimental or control group. The experimental group drank a high caffeine soda, while the control group drank a caffeine-free soda. He then measured and compared arousal states for both groups. What type of design did Pete use?

A) interrupted time series
B) two-group posttest-only design
C) classical experimental
D) pretest-posttest