The answer to this question would be lifting weights.
Anaerobic means "without oxygen". The chemical reaction to make energy is either aerobic which was "using oxygen" or anaerobic. When the intensity is low, oxygen is used because it gives more energy. But using oxygen has a limit, so if the intensity is too high anaerobic reaction will happen. Anaerobic exercise means that the exercise that will use up so much energy in a short time so that the aerobic reaction can't fulfill the energy demand. It should be sprinting or lifting weights.
Sorry i'm late, but I know that it isn't tennis. So that is one answer ruled out. I wish I could help you more but honestly, I just finished that test and got the question wrong. So it defiantly isn't tennis. The option that makes the most sense to me would be lifting weights or running. 50/50 chance. Sorry again that I couldn't give you an actual answer but I hope this helps rule out an option at least.
When a chemical signal pops up on one side, it tells the cell to expand its shape on that side, because the cell is constantly touching and pulling at the environment.
