Where's the choices?? But anyways cardio has to do directly with the heart and it's pace if I do crunches that is NOT cardio respiratory it's neither cardio respiratory hope this helps
In human exchange of gases takes place in alveoli in lungs
In plants it occurs in leaves through stomata
In fishes it occurs through gills
All of the reasons you've listed are actually reasons why one might do physical training. A lot of people who do physical training do it for different reasons, whether that reason is pleasure, endurance, strength or just peer approval, is up to them. However, each one of them can be seen as a reason for physical training.
The answer is d I think
Hope this helps
