With Regard to Getting Problem-Specific Data

With regard to getting problem-specific data:

A) the observation method involves asking consumers direct questions about their observations.
B) surveys distributed by e-mail are declining in popularity.
C) focus group interviews are usually more representative than a set of personal interviews.
D) telephone surveys are limited to short, simple questions--they don't allow the interviewer to learn what a respondent is really thinking.
E) None of the above is a true statement.