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: Pathology
Paul -Bunnell test is positive in: 
Select and explain. 
A. Infectious mononucleosis, B. Multiple myeloma, C. Malignant nerves, D. Rubella
A: Infectious mononucleosis
Answer: A: Infectious mononucleosis 
Explanation: None