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The question is...

12. For a test of the hypothesis, the mean is less than 0.75 at the 2% significance level, what can be said about the probability of committing the type one error (be brief, but precise)?
A. exactly 0.02
B. exactly 0.98
C. at least 0.02
D. at most 0.02
E. at most 0.01

D. at most 0.02