The correct statement about lymphocytes is: b) Lymph transport depends on the movement of adjacent tissues such as skeletal muscles.
Explanation: Lymph transport, unlike blood circulation, does not have a central pump like the heart. Instead, it relies heavily on the movement of surrounding tissues, particularly skeletal muscles, which help propel lymph through the lymphatic vessels. As these muscles contract during physical activity, they squeeze the lymphatic vessels, facilitating the flow of lymph. This is crucial for maintaining the immune system’s efficiency and ensuring that lymphocytes are effectively transported throughout the body. On the other hand, option a is incorrect because lymph transport is generally slower than blood flow in veins, and option c is misleading as lymph transport is a continuous process necessary for fluid balance and immune function, not just during illness.