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.