Which of the following is only a muscle-strengthening activity that can be completed in school? a. running b. sit-ups c. jumping d. stretching

Which of the following is only a muscle-strengthening activity that can be completed in school? The 

situps are the muscle strengthening activity running and also jumping are both cardio and by the way stretching just as to warms up the muscles in your body.

Hope this helps you out 

It would be sit- ups because you are improving your core and your abdominal muscles. Hope this helped!