Which of the Following Would Be Most Helpful in Assessing $\alpha$

Which of the following would be most helpful in assessing the practical significance of a test of hypotheses about a proportion?

A) Test the hypotheses using significance level $\alpha$ = 0.001.
B) Report the P-value of your test.
C) Take another sample and retest just to make sure the results are not due to chance.
D) Construct a 99% confidence interval for the proportion in order to see the magnitude of the proportion.