DrEwell,a Developmental Psychologist,is Planning on Conducting a Study That Involves

Dr.Ewell,a developmental psychologist,is planning on conducting a study that involves watching children play together to determine how sharing behavior occurs in same-sex friend pairs compared to opposite-sex friend pairs.

-Given the scenario above,Dr.Ewell is concerned that the children will behave differently because of the presence of research assistants.Which of the following could he do to address this concern?

A) Make the observations himself instead of using a research assistant
B) Have two undergraduate research assistants make the observations instead of just one
C) Observe the same-sex friend pairs on the first day and the opposite-sex friend pairs on the second day
D) Hide a video camera in the daycare center and record the children playing without them knowing