How Is Income Linked to the Likelihood That People Vote

How is income linked to the likelihood that people vote in presidential elections?

A) There is no clear link; people of all income levels are equally likely to vote.
B) "Self-made" people are more likely to vote than those who inherit wealth.
C) The higher the income, the greater the share of people who vote.
D) The lower the income, the greater the share of people who vote.