In TB, immunity is provided by -

Ans. is 'a' i.e., CD4+ . Cell mediated immunity confers protection against M. tuberculosis, while humoral immunity has no defined role in protection. . Two types of cells are essential. 1. Macrophages --> Directly phagocytize tubercle bacilli. 2. T cells (mainly CD4+) --> Induce protection through the production of IFN-y