To understand the unusual behavior of an adult client, a psychologist carefully investigates the client’s current life situation and his physical, social, and educational history. Which research method has the psychologist used?

The Case Study

Explanation:

Case studies usually involve the detailed study of a particular case (a person or small group). Various methods of data collection and analysis are used but this typically includes observation and interviews and may involve consulting other people and personal or public records. The researchers may be interested in a particular phenomenon (e.g. coping with a diagnosis or a move into residential care) and select one or more individuals in the respective situation on whom to base their case study/studies. Case studies have a very narrow focus which results in detailed descriptive data which is unique to the case(s) studied. Nevertheless, it can be useful in clinical settings and may even challenge existing theories and practices in other domains.

i do believe that the correct answer is   (technical reasoning); luck

explanation:

the answer is:

c. economic output