If your lymphatic system stopped working properly fluid would build in your tissues and cause swelling. You could get infections, blockage and even cancer. If your immune system stopped working properly too then you would most likely die. Since your lymphatic system is down and your immune system is down it would weaken your body tremendously meaning the smallest cold could cause death.
The answer is...
B) To ensure that you are constantly engaging your body in a way that improves its function
I am an organ donor. I believe that if my body can make someone survive an illness (cancer/leukemia) or recover from a condition such as blindness or a missing limb, then It is my duty to allow for that to happen. When I die, my soul will go on but my body will just rot so why not let someone use up what they can. I am especially strong in my opinion when dealing with pediatric illnesses. If a child needs my lungs or my kidneys, they should take them and live a long life. After I pass, they are useless to me!