In a Laboratory Experiment on Helping Behavior, Two Variables Are

Multiple Choice

In a laboratory experiment on helping behavior, two variables are manipulated: (1) others' presence (whether participants worked alone on a task or with others) and (2) type of task (whether participants were timed or untimed on the task) . The dependent measure is the number of seconds between someone's request for help and the participant's response. What type of experimental design is this?

A) posttest-only control group design
B) pretest-posttest control group design
C) 2 × 2 factorial design
D) 2 × 4 factorial design