cause the arteries to expand. decrease the heart rate. increase the heart rate. send fewer signals.
I gave my students this multiple choice question: In the heart there is a group of specialized cells that regulates the frequency of the heartbeat. During strenuous exercise, the group of cells will most likely

Only one answer is correct among these 4 choices:
- cause the arteries to expand.
- decrease the heart rate.
- increase the heart rate.
- send fewer signals.

Could you tell me which one is correct?

increase the heart rate.