The confidence interval method for hypothesis testing (at the 95 percent level) relies on the fact that:

a. 95 percent of all sample statistics are correct.

b. the observed sample statistic is correct 95 percent of the time.

c. There is a 95% chance that the calculated confidence interval contains the true value of the unobserved population parameter

d. 95% of all confidence intervals that could be contain the true value of the unobserved population parameter.

Personally, I think the answer is a, but I need a confirmation. Thank you.