Answer:
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.
Step-by-step explanation:
A type I error occurs if you reject the null hypothesis when it is true.
Now the hypotheses are:

The proportion is 0.398

The proportion is less than 0.398
If in actual fact the proportion is 0.398, then the president must not reject the

.
This is a correct decision.
If in actual fact the proportion is 0.398, and the president rejects the

, then a type I error is committed.
The correct choice is C.