It’s C because most exercise machines require less skill to use than free weights.
All of the above is the correct answer
B the deliverance of oxygen rich blood to muscles by the heart lungs and vascular system .. i believe
That statement is true
Aerobic exercise such as swimming and running will burn a lot of calories from our body
And in order to burn calories, our body need supply of oxygen.
That's why our heart tend to beat really fast when we do Aerobic exercise, it's because our heart need to pump a lot of blood to deliver oxygen to the muscles