An Older Adult Client Is Being Assessed by the Nurse

An older adult client is being assessed by the nurse. The client states, "I seem to get sicker more often. I was a robust and healthy person for many years." In which manner does the nurse explain the theory of immunosenescence and aging?

A) Natural killer cells become sparse and less effective.
B) T lymphocytes have a decreased ability to recognize and attack antigens.
C) B lymphocytes become more effective in producing antibodies to antigens.
D) Immunizations are vital to boost the immune system and promote health.