The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Which cells are decreased in chronic periodontitis?   (A) B-lymphocytes   (B) T-lymphocytes   (C) Mast cells   (D) Plasma cells
['(B) T-lymphocytes <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) B-lymphocytes \n (B) T-lymphocytes \n (C) Mast cells \n (D) Plasma cells <> possible answers', '  Which cells are decreased in chronic periodontitis? <> context@']