A New Nursing Student Is Taking a Tuberculin (TB) Skin

A new nursing student is taking a tuberculin (TB) skin test as part of her preparation for beginning clinical placement in the hospital.The student is unclear of the rationale or physiology involved in this test. Which of the following is the correct explanation?

A) The cell-mediated hypersensitivity associated with Mycobacterium tuberculosis remains detectable for several years.
B) Formation of contact dermatitis lesions confirms prior TB contact.
C) ^{Previous TB exposure forms sensitized T}h^{1 cells that are long-lived.}
D) This type of delayed-type hypersensitivity (DTH) is a response to latent Mycobacterium tuberculosis bacteria.