This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Pharmacology
[{'content': 'Which of the following drug is an Immunostimulant? \nSelect and explain. \nA. Prednisolone, B. Levamisol, C. Cyclosporine, D. Thalidomide', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (Ref: Goodman & Gliman 11/e p1422) All other drugs listed in the options posses immunosuppressant propeies.', 'role': 'assistant'}]