Answer:
The Skeletal system helped him move his hand away from the hot object.
Explanation:
The Skeletal system consists of our skeleton or the bones. The other options would be correct if the question asked about the<u> nervous system</u> instead of the skeletal system.
The kidneys.
The kidneys keep blood isotonic by removing excess salt and water through urine.
9.organ system, 10. organ level I guess.
