This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology Pa 1 (Immune Response, Antigen-Antibody Reactions, Hypersensitivity, Structure of Immune System, Immunodeficiency Disorders), Subject name: Microbiology
[{'content': 'Myasthenia gravis is which type of hypersensitivity- \nSelect and explain. \nA. Type I, B. Type II, C. Type III, D. Type IV', 'role': 'user'}, {'content': "Answer: B \nExplanation: In mystenia grevis antibodies are directed against Ach Receptors so this a type 2 hypersensitivity reaction. 1. Type II cytotoxic reaction is mediated by antibodies directed against antigens on the cell membrane that activates complement thereby causing antibody-mediated destruction of cells. The cell membrane is damaged by a membrane attack complex during activation of the complement. eg:-Stimulation- Grave's disase (LATS), Inhibition - Myasthenia gravis (Anti Ach receptor Ab) 2.Type 1 rxn lead to anaphylaxis. 3. Type 3 rxn.is antigen antibody complex mediated rxn. Myasthenia gravis, an autoimmune disease", 'role': 'assistant'}]