This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
The dreaded complication of Rituximab is: 
Select and explain. 
A. Progressive multifocal leukoencephalopathy, B. AIDP, C. Bone marrow suppresion, D. Cardiac toxicity
A: Progressive multifocal leukoencephalopathy
Answer: A: Progressive multifocal leukoencephalopathy 
Explanation: The dreaded complication of Rituximab is progressive multifocal leukoencephalopathy Ref: Harrison's principles of internal medicine, 18th edition ; Page 882.