Answer:
D, they are all the same size.
These unsegmented worms have a full digestive system even when parasitic.
Im going with Genes inserted from other organisms.
The function of the digestive system<span> is </span>digestion<span> and absorption.</span>Digestion<span> is the breakdown of food into small molecules, which are then absorbed into the body. The </span>digestive system<span> is divided into two major parts: The </span>digestive tract<span> (alimentary canal) is a continuous tube with two openings: the mouth and the anus.</span>
3 is the correct answer. Let me know if you want me to explain why that is the answer.
