In __________,researchers interact naturally with the people they are studying,but do not reveal their identities as researchers.

A) participant observation
B) non-participant observation
C) survey research
D) clinical research

Participant observation involves researchers immersing themselves in the environment they are studying and observing and experiencing things firsthand. In some cases, researchers may choose to hide their true identity as researchers to prevent changing the behavior of the participants. This allows them to gain more accurate information about the participants' natural behavior and interactions within their social context. Non-participant observation would involve observing from a distance without interacting with the participants at all. Survey research involves administering surveys or questionnaires to participants to gather information, while clinical research involves studying people with a specific condition or disease. Therefore, the best choice is A) participant observation.