A 55-Year-Old Patient Tells the Nurse That He Seems to Be

A 55-year-old patient tells the nurse that he seems to be getting "more colds" as he gets older.Which possible explanation would the nurse have for this observation?

A) Aging causes the immune system to have difficulty determining self from non-self cells.
B) With aging,the body has increased difficulty recognizing mutated cells.
C) The thymus gland shrinks with aging,reducing the maturation and differentiation of T cells needed to fight infections.
D) The thyroid gland begins to malfunction after the 4th decade of life.