Which of the following is a type i error?

a. the president fails to reject the hypothesis that the proportion of students who earn a bachelor's degree within six years is 0.398, when, in fact, the proportion is 0.398.
b. the president rejects the hypothesis that the proportion of students who earn a bachelor's degree within six years is 0.398, when, in fact, the proportion is less than 0.398.
c. the president rejects the hypothesis that the proportion of students who earn a bachelor's degree within six years is 0.398, when, in fact, the proportion is 0.398.
d. the president fails to reject the hypothesis that the proportion of students who earn a bachelor's degree within six years is 0.398, when, in fact, the proportion is less than 0.398.