Which of the following can cause muscle fatigue ? A. A build up of lactic acid
b. an inadequate supply of oxygen
C. an inadequate supply of glycogen
D. all of the above​

The correct answer is -all of the above.

Explanation:

Muscle fatigue is a reduced ability in work capacity caused by work itself. It is known that altering oxygen is contracting skeletal muscle affects performance. Reduced O2 supply increases the rate of muscle fatigue.

The lactic acid is accumulated as it forms rapidly but the breaking of the lactic acid is slow down, which causes muscle fatigue. Less ATP and glycogen in muscle results in fatigue as the muscle is not able to generate energy to power contractions and therefore contributes to muscle fatigue.

i believe the answer is c. "baking" is the gerund, while "baking blueberry muffins" would be the gerund phrase. hope this ! : )