Skeletal Muscle is not involved in...(multiple choice)

A. Movement of skin
B. Propulsion of a substance through a body tube
C. Heat production
D. Inhibition of body movement

(can have more than one answer if more than one correct answer is listed)

B. Smooth muscle forms the body tube

Now I think about it:

B

But there is a problem with B. What is meant by "body tube". Veins are "Body tubes" and skeletal muscles ARE involved in propelling blood against gravity in the legs by contraction.... but then smooth muscle is related to the small intestine and oesophagus. so it must be B.