What is not a method that maintains lymph flow?

Capillary smooth muscle contraction.

Explanation:

Actually, the above question in incomplete as the full question contains these choices.

The answer for this question is capillary smooth muscle contraction because lymph flow in one direction.

Valve in lymph vessels walls pushed the lymph forward and stop it from back flow.

Muscles present surrounding the lymph vessels help in flow of lymph by their massaging effect.

Deep diaphragmatic breathing helps in the movement of lymph through blood stream and increases toxins elimination.