Which is the following is true of polls?

A) Reliable polls use a sample that is representative of the entire population.
B) Phoning people at home at dinner time is best method for conducting a poll.
C) Polls are rarely reliable.
D) None of these answers is correct.

If a poll uses a sample that is not like the general population, the poll will not be reliable. It may accidentally get the right result, but it provides no good reason to believe its conclusion. Random selection is often a good way to ensure that the sample is representative, but occasionally random samples will be misleading, and those conducting the poll must choose people based on some characteristic that would be underrepresented by a random sample.