Step-by-step explanation:
Lymph moves through the body via the contraction of muscles surrounding the lymphatic vessels. The movement of the skeletal muscles during physical activity helps to squeeze the lymphatic vessels, propelling the lymph forward. Additionally, the valves within the lymphatic vessels prevent backflow and assist with the movement of lymph towards the heart. The spleen, heart, and lungs do not play a significant role in moving lymph through the body.