I believe the best option to your question will be A.
The answer is loss of muscle tissue. When you lose weight, you lose fat but if you
continue to lose weight and the fat has been lost then and you would start losing
muscle tissue. This gives the person a
gaunt-like appearance especially when he or she overdoes it.
The lymphatic system is a rather important system in the body. Using its pathways it both takes toxins and waste products to other parts of the body, and also help regulate the interstital fluid between tissues.
Additionally the lymphatic tissue is a major pathway of lynphocytes which travel through lymph (clear fluid with lymphatic cells).
Your answer is "A"