Which of These Sociology Students Is Engaging in Participant Observation

Multiple Choice

Which of these sociology students is engaging in participant observation?

A) John watches preschool students who are not aware he is there.
B) Mary visits a first-grade classroom to conduct a study on teacher-student interactions and helps out in the classroom as a para-educator.
C) Bill sits on a park bench and observes behavior without people's knowledge.
D) Sue observes medical students working on a patient without his or her knowledge that she is present.