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
Earliest sign of OSMF: 
Select and explain. 
A. Burning sensation, B. Blanching, C. Restricted mouth opening., D. Circum oral bands.
B: Blanching
Answer: B: Blanching 
Explanation: Earliest complaint : burning sensation
Earliest sign : blanching