Your answer would be A, because skeletal muscles are your muscles that allow your bones and joints to move. Answer A is an example of your involuntary muscles, which are not the same as skeletal muscles. I hope you still have time to put the correct answer down on your test, but if not please make me the brainliest answer, because my answer is actually correct.
Simply walking alone can actually do both of these however if you are looking for multiple answers then here are some examples:
-Playing Sports
-Jogging
-Lifting Weights
-Swimming
-Dancing
-Bike Riding
etc...
Anyways, hope I helped!