Which of these methods would be most effective in allowing someone to precisely gauge the intensity level of his exercise? a: complete the talk test
b: ask a coach
c: take his pulse
d: monitor his water intake

The answer is C because doing a talk test or asking a coach don't measure someone's intensity levels. And the answer isn't D because a person might drink a lot of water at one time, but that doesn't mean that he/she is in an intense state. And so the answer is C because it correctly measures a person's intensity level because if a person is really intense, he or she would have a rapid heart rate.