The best answer is C.
When an individual suffers a bacterial infection in the legs, immune proteins called acute phase proteins bind to the surface of the bacteria by a process called opsonisation.
Opsonised bacteria are therefore coated with molecules (self antigens) that phagocytic cells recognize. Activated phagocytes engulf and destroy opsonized bacteria by "swallowing " (engulfing) them.
Inside the phagocyte, enzymes break down the bacteria onto small fragments just the way food is broken down by enzymes in the digestive system. Phagocytes then present the fragments on their surface which helps in the final destruction of the bacteria within the phagocyte.
