A. Chyle is a type of lymphatic fluid rich in fats absorbed from the intestines, but it is not the primary basis of all lymphatic fluid. B. Secretions of lymph nodes contribute immune cells and filtering functions but do not form the main component of lymph. C. Plasma is the correct answer. Lymphatic fluid originates from interstitial fluid, which in turn is derived from plasma that leaks out of capillaries. This fluid enters the lymphatic system and becomes lymph. D. MALT (Mucosa-associated lymphoid tissue) is involved in immune responses in mucosal membranes but does not form the basis of lymphatic fluid.