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: Anatomy
Which of the following drug is an immunostimulant 
Select and explain. 
A. Prednisolone, B. Levamisol, C. Cyclosporine, D. Thalidomide
B: Levamisol
Answer: B: Levamisol 
Explanation: Ref-Goodman and Gillman 11/e p1422 All other drugs listed in the option posses immunosuppressant propeies