Which mechanisms is not used to propel lymph through lymphatic vessels?

small heart-like pumps

Explanation:

Here is the complete question:.

Which of the following mechanisms is NOT used to propel lymph through lymphatic vessels?

small heart-like pumps

gravity

the milking action of muscles

pulmonary motion

And the answer is

small heart-like pumps

answer; /// i believe the correct answer is (reactants);