Answer:
B. You can talk but cannot sing during the exercise.
Step-by-step explanation:
During moderate activity, your heart and breathing rates increase, but you can still converse easily. It is a level of exertion that is challenging but sustainable. While engaging in moderate activity, you may feel slightly out of breath, increase your heart rate, and break a sweat. However, you should still be able to speak in complete sentences without feeling too winded.
On the other hand, if you can sing comfortably during the exercise, it indicates that the activity is at a lower intensity, likely classified as light activity. Singing requires more breath control and lung capacity than talking, so if you can sing while exercising, it suggests that the activity is not providing enough cardiovascular challenge to be considered moderate.