This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunomodulator, Subject name: Pharmacology
[{'content': 'Rituximab is a targeted antibody against - \nSelect and explain. \nA. CD 20, B. CD 22, C. CD 34, D. CD 55', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., CD 20 * Rituximab is a targeted antibody against cell surface molecule CD-20, i.e. Rituximab is anti CD-20 antibody.* It is used in:i) B-cell lymphomas Low grade lymphomas, mantle cell lymphomas, relapsed aggressive B cell lymphomas, CLLii) SLEiii) Rheumatoid arthritis", 'role': 'assistant'}]