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: ENT
Not a differential Diagnosis for grey white membrane on Tonsil 
Select and explain. 
A. Candidiasis, B. Ludwig's Angina, C. Vincent's Angina, D. Malignancy tonsil
B: Ludwig's Angina
Answer: B: Ludwig's Angina 
Explanation: None