A psychologist designed a study to test the effects of cell phone use on driving safety. Participants were randomly assigned either to drive an automobile simulator while talking to a friend on a cell phone or to drive a simulator without talking on a phone.

Which type of research does the scenario describe?
a. Participant Observation
b. Naturalistic Observation
c. Correlation Study
d. Case Study
e. Experiment

'Experiment' is demonstrated as the research method that aims to investigate a hypothesis objectively. Such a research method aims to observe and evaluate the changes in a dependent variable by manipulation of the independent variable.

As per the given description, the 'experiment' is the kind of research that has been demonstrated as the researcher aims to demonstrate the validity of the truth('effects of cell phone use on driving safety'). The researcher controls the independent variable by 'randomly assigning the participants to drive the automobile simulator while talking to their friend' to observe its impact on the dependent variable 'driving safety'. Therefore, option E is the correct answer.