Voters in Presidential primaries and caucuses tend to be
a. far less educated and much poorer on average than the United States population as a whole.
b. somewhat less educated and somewhat poorer on average than the United States population as a whole.
c. very similar to the rest of the United States population in terms of education and income.
d. older and more affluent than the United States population as a whole.
e. minorities and notably younger than the general population.