Which of the following is true about cardio fitness? A. Cardio activities are also known as aerobic activity.
B. Cardio activities are recommended on a daily basis.
C. When performing cardio activities, your heart rate should be within your target heart rate zone.
D. All of the above.

D. All of the above

Explanation:

All of these answers make complete sense to the question, Cardio is healthy for you and should be done on a daily basis.

age might have something to do with behavior depending on the age because not everyone who is the same age acts the same like 2 year olds could have bad behavior but some won't.

i hope this : )