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
Aphthous ulcers known as - 
Select and explain. 
A. Canker sores, B. Marjolin's ulcer, C. Curling's ulcer, D. Cushing ulcers
A: Canker sores
Answer: A: Canker sores 
Explanation: Ans. is 'a' i.e., Canker SoresAphahous ulcers o Also known as Canker Soreso These are superficial Ulcerations of oral mucosa.o The lesions may be Single or multiple.o Ulceration is surrounded by an erythematous halo and is Covered by a thin exudate.