Identify the Type I Error or Type II Error as Indicated

Identify the Type I error or Type II error as indicated.
-The average diastolic blood pressure of a group of men suffering from high blood pressure is 100 mmHg. During a clinical trial, the men receive a medication which it is hoped will lower their blood pressure. After three
Months, the researcher wants to perform a hypothesis test to determine whether the average diastolic blood pressure of
The men has decreased. The hypotheses are: $$\begin{array} { l } \mathrm { H } _ { 0 } : \mu = 100 \mathrm { mmHg } \\\mathrm { H } _ { \mathrm { a } } : \mu < 100 \mathrm { mmHg }\end{array}$$
Identify the Type II error.

A) Fail to reject the claim that the average diastolic blood pressure is 100 mmHg when in fact it is less than 100 mmHg.
B) Fail to reject the claim that the average diastolic blood pressure is 100 mmHg when in fact it is 100 mmHg.
C) Reject the claim that the average diastolic blood pressure is 100 mmHg when in fact it is 100 mmHg.
D) Reject the claim that the average diastolic blood pressure is 100 mmHg when in fact it is less than 100 mmHg.