Match each risk factor to its type.
a. controllable risk factor
someone else driving while drowsy
b. uncontrollable risk factor
swimming alone

Swimming along is a controllable risk factor, because you can stop whenever you want if you see some risk around.

On the other hand, someone else driving while drowsy represents an uncontrollable risk factor, because your are not the one who is driving, so the outcome doesn't depend on you, but the current driver, who is also drowsy, which increase the risk.