Answer:
Controlled observation.
Step-by-step explanation:
Controlled observation: This is one of the structured-observational study in which all the conditions are strained by the researcher only. The controlled observation might be carried out in a psychological laboratory setting and high in control because variables are being manipulated.
In this type of research, the researcher has all the powers to make decisions regarding the study, i.e, time and place of observation, circumstances, group of participants, and uses standardized procedure.