Respondents Are Often More Comfortable Addressing Sensitive Subjects on Surveys

Respondents are often more comfortable addressing sensitive subjects on surveys than in other research contexts because

A) they know that many other people will answer the same questions.
B) they know that their answers will only be analyzed statistically.
C) they can answer in private and are usually assured anonymity.
D) surveys guarantee that their answers will be confidential, while other methods do not.