Not an instructor, but I didn't pick C because it says that introverted people "sense" the rise in blood pressure. The conclusion is that it's the stress of communication and not the exertion of speaking that causes the rise in blood pressure. Introverted individuals "sensing" the rise in blood pressure when they speak doesn't strengthen that conclusion because it doesn't tell us that this rise is due to the stress of communicating as opposed to just the physical exertion of speaking.
I picked D, because it said that Deaf individuals experience a rise in blood pressure when they are signing (communicating), but not when they move their hands for other reasons (physical exertion). Deaf individuals are moving their hands (exerting themselves physically) during both of these activities, but we only see the rise in blood pressure when they are using their hands to communicate. So this strengthens the conclusion that it is the stress of communication as opposed to the physical exertion of communicating that is causing this rise in blood pressure.
Emil-KunkinJanuary 19, 2022
Hi @yulissacardoza, I love Ellison's explanation. We are looking to strengthen the idea that blood pressure rises due to the stress of communicating, rather than due to the physical act of speaking. D offers us an example of communication without speaking, and shows the same result with blood pressure. Another issue with C is the concept of "chronically high blood pressure." The stimulus does not mention if the participants have high blood pressure or not, and C introduces a new and unrelated complication.
