Answer:
c. survey
Explanation:
Randy is a community psychologist working with a community AIDS organisation on a project to help reduce HIV transmission. He wants to get as much information from as many people as possible about their sexual lifestyle. Since he wants to get the information from as many people as possible the best choice of research should be a survey.
Survey research is a process or method of collecting information from a sample of population to gain insight in a particular field of study. The information collated from these individuals are used to understand their knowledge, behavior and attitude. The survey or the extraction of this form of data can be done in person , online , phone or on paper.
The best choice to gather information about people sexual pattern is using survey technique. Many people can be studied through this means. First hand information can be gotten also.