In Which of the Following Research Questions Is Income a Dependent

In which of the following research questions is income a dependent variable?

A) Does college GPA increase a new graduate's income in the first year after graduation?
B) Does parental income predict a child's college GPA?
C) Are students whose parents are wealthy more likely to receive merit-based scholarships than those whose parents are not?
D) Which is more influential over a child's acceptance into a prestigious university: parental income or student GPA?