The correct option is C Circulatory system.
As blood which is a part of circulatory system passes through the tissues of the body, it enters thin-walled capillaries called lymph capillaries. Lymph is the fluid formed when the interstitial fluid is collected through lymph capillaries. It circulates through the lymphatic system. It contains proteins, salts, glucose, fats, water and white blood cells. It does not contain any red blood cells. Hence it is colorless. Thus the correct answer is option C.