Really, none of these answers are good. leukocytes are the body's general immune cell, and lymphocytes are a type of leukocyte. Antibodies are only used when fighting an infection that your body already has experience with, so I'm guessing it you have to pick from these answers, its "lymphocytes", but it's not really the best answer.
Answer:
Answer at the bottom!!
Explanation:
Skeletal muscles are voluntary muscles, which means you can control what they do.
Hope this helps!!
All of them could be intentional/unpreventable, we are only talking about an injury so I would say the plane crash.