<prompt> Centre of tubercular granuloma is formed by -T-lymphocytesB-lymphocytesLanghans giant cellsNecrotic zone  <response>: Ans. is d i.e.,Necrotic zone Tubercular granulomaTubercular granuloma contains mostly blood-derived macrophages, epithelioid cells differentiated macrophages and multinucleated giant cells also known as Langhans giant cells, surrounded by T- lymphocytes.Caseous granulomas are typical of tuberculosis. These structures are formed by epithelioid macrophages surrounding a central cellular necrotic region with a rim of lymphocytes of the T- and B-cell types. 