Random Sampling in Public Opinion Polling Operates on the Principle

Random sampling in public opinion polling operates on the principle that

A) the answers to include in aggregate poll results must be selected by chance in order to maximize accuracy.
B) everyone should have an equal probability of being selected.
C) the questions to be asked of a given respondent must be selected randomly so that all respondents are asked the same question the same number of times.
D) the larger the number of people who are polled,the greater the accuracy of the poll.
E) Both b and c are true.