Which method should a psychology researcher use if she is interested in testing whether a specific reward in a classroom situation causes students to behave better

Experiment

Explanation:

An experiment is simply said to be a planned inquiry or an investigation. psychologist are concerned with how to describe, explain, predict, and change behavior and the use of experiment helps them achieve their goal.. Usually, psychologists does experiments to know the probability of having a cause-and-effect relationship between different variables e.g when a researcher studies on if starving yourself of sleep affects the way you perform on a swimming test. experiment is the only research method mentioned here that allows the manipulation of an independent variable to test causation

the branch of biology that deals with the normal functions of living organisms and their parts.

the way in which a living organism or bodily part functions.