A patient is administered a tuberculin test. Which of the following types of hypersensitivity reaction is being tested, and which cells would be expected to mediate a positive test result?
(A) Type I hypersensitivity, mast cells
(B) Type II hypersensitivity, cytotoxic T lymphocytes
© Type IV hypersensitivity, mast cells
(D) Type IV hypersensitivity, T-helper 1 cells
(E) Type IV hypersensitivity, T-helper 2 cells