Irrelevant— we don’t know whether introverts or extroverts are taking more blood pressure medication. Regardless, the fact that the medication doesn’t reduce blood pressure increases caused by speaking does nothing to strengthen the argument.

Irrelevant— we don’t know whether introverts or extroverts have a lower typical blood pressure. Either way, (B) is simply affirming that blood pressure increases under stress. It isn’t helping us to figure out why blood pressure increases while speaking.

Irrelevant—whether some introverts notice their blood pressure rise while speaking doesn’t change the fact that it is rising. We need an answer that explains why it’s rising. Also, as far as we know, extroverts might notice the increase too.

This suggests that physical exertion isn’t causing the blood pressure increase. Since deaf people’s blood pressure rises when they communicate through sign language, but not when they move their hands, it suggests the increase is due to communication, not physical movement.

This weakens the argument by offering an alternative explanation for the difference in blood pressure between extroverts and introverts. If extroverts tend to have high blood pressure and take medication, the difference could be due to the medication, not stress.