They breathe through their skin. Air dissolves on the mucus of their skin, so they MUST stay moist to breathe.
If worms dry out, they suffocate. As fresh air is taken in through the skin, oxygen is drawn into the worm's circulatory system, and the worm's hearts pump the oxygenated blood to the head area.
B is your answer. God Bless hope this helps
Answer: Around 37.2 trillion cells
that is has a nucleus and also a cell wall
