The correct option is B Repressor
T cells or T lymphocytes are a type of lymphocyte that provides cell-mediated immunity. There are different types of T cells. They are listed below.
a. T- helper cells which assist other WBCs in immunologic process.
b. Cytotoxic T cells destroy virus-infected cells and tumor cells.
c. Suppressor T cells are crucial for the maintenance of immunological tolerance.
Therefore, the correct answer is option D.