Answer:
a. The individual's blood pressure is unusually high, compared to others
Step-by-step explanation:
The individual's blood pressure is unusually high, compared to others. Since the z- score is positive, it implies that the individual's blood pressure is higher than the average blood pressure of others. And also given that the z-score is as high as 2.1 (higher than 95% confidence interval which is 1.96) implies that the individual's blood pressure is extremely higher than the average blood pressure of others.