please give the why or why not's of each answer rather right or wrong?

A new blood pressure lowering medication is tested on a group of patients. The average systolic blood pressure of patients who did not receive the medication is 138 mm Hg, and the average systolic blood pressure of patients who did receive the medication is 126 mm Hg. A t-test was used to compare the two outcomes. The 95% confidence interval was 10.23 to 13.77, and the 99% confidence interval was 9.68 to 14.33. The null hypothesis is that there is no difference between the groups.

What is the correct interpretation of this study's results

a. Using the 95% confidence interval, one fails to reject the null hypothesis.

b. Using the 99% confidence interval, one fails to accept the null hypothesis

c. increasing the confidence interval from 95% to 99% decreases the probability of accepting the null hypothesis.

d. Increasing the confidence interval from 95% to 99% decreases the probability of rejecting the null hypothesis.