Psychology is commonly defined as the scientific study of behavior and mental processes observation and measurement of human and nonhuman behavior private internal experience and anything we do study of the mind and body

The correct answer in the given choices above is the first choice which defines psychology as the scientific study of behavior and mental processes. It is because in Psychology, it usually focuses in studying the person's action or behaviors in certain events, happening in their environment or particular thing in relation to how they perceive or think about them. They focus more on the mind and how they behave towards to other people and the environment.