Which of These Characterizes a Representative Sample?​

Multiple Choice

Which of these characterizes a representative sample?​

A) Anyone who volunteers to participate is included in the study.
B) ​Everyone in the population has an equal chance of being chosen for the study.
C) ​The percentages of male and female, old and young, match the whole population.
D) ​The people in the study say they are confident that their opinions are the common ones.