In a simple random sample, ________.

A、 every member of the population has a known and equal chance of selection
B、 the population is divided into mutually exclusive groups (such as blocks), and the researcher draws a sample of the groups to interview
C、 the researcher selects the easiest population members from which to obtain information
D、 the population is divided into mutually exclusive groups and random samples are drawn from each group
E、 the researcher finds and interviews a prescribed number of people in each of several categories