In Public-Opinion Surveys, a Sample of the Total Population

In public-opinion surveys, a sample of the total population

A) must be at least 50 percent of the targeted population.
B) need be only 25 percent of the targeted population.
C) must be representative in that the views of those in the sample must accurately and proportionately reflect the views of the whole population.
D) must be based on all the registered voters in the targeted population.