Dr Frank Wants to Study the Queer Sexual Practices of Men

Dr. Frank wants to study the queer sexual practices of men aged 40 to 50 in religious societies. He employs the survey research method to record their behavior. In order to collect the data most efficiently and eliminate the limitations caused by self-reporting, Dr. Frank must

A) collect personal notes from volunteers that document their sexual activities on a daily basis.
B) arrange for video conference in which volunteers can answer sex-related questions.
C) conduct face-to-face interview with volunteers.
D) write down his observations about the volunteers and refrain from asking them for data.