The local police department has come to a criminologist to help them evaluate a new type of disposable, plastic handcuffs. They are just as effective as metal handcuffs in terms of immobilizing someone who has been arrested and they are cheaper than metal handcuffs, but the police are concerned that the plastic ones might cause more abrasion to the skin of the wrist. The criminologist finds 20 volunteers, randomly divides them into two groups, cuffs one group with metal and the other with plastic, and then rides them around in a squad car for 20 minutes. After this, the criminologist measures the degree of abrasion on their wrists as the percentage of skin that is roughed up.

a. Generate a sentence that states the question the researcher is trying to answer.
b. List the variables and label them as independent and dependent.
c. Determine what type of study is being done: correlational, experimental, or quasi-experimental.
d. If the study is correlational or quasi-experimental, come up with a plausible confounding variable and explain how it affects both variables.