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
A case presenting with a gray coloured pseudomembrane
whose removal is difficult and painful, can be 
Select and explain. 
A. ANUG, B. Diphtheritic lesion, C. Secondary stage of syphilis, D. Desquamative gingivitis
B: Diphtheritic lesion
Answer: B: Diphtheritic lesion 
Explanation: None