Professional Sample Surveys Use Careful Random Samples, Usually by Randomly

Professional sample surveys use careful random samples, usually by randomly dialing telephone numbers, to come close to an SRS. But the results that a sample survey actually obtains may be strongly biased because

A) the typical sample size of 1000 or 1500 people is too small.
B) the margin of error is too large.
C) surveys report only what their sponsors want to hear.
D) many people refuse to respond to telephone surveys.