Why Do Social Scientists Who Use Interviews Rarely Speak with Large

Why do social scientists who use interviews rarely speak with large numbers of people for a project?

A) It is hard to find people willing to be interviewed.
B) The transcription process takes a long time.
C) There are usually very few people who are interesting enough to be interviewed.
D) Face-to-face interviewing is a very time-consuming process.
E) The data is so rich that few interviews are typically needed.