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: Dental
A patient gives a history of recurrent oral ulcers. The ulcers are small with a yellow floor surrounded by an erythematous halo on the lips. He also has multiple, tender nodules on the skin. He most likely has- 
Select and explain. 
A. Behcet's syndrome, B. Herpes labialis, C. Fixed drug eruption, D. Pemphigus vulgaris
A: Behcet's syndrome
Answer: A: Behcet's syndrome 
Explanation: This patient has : -


Recurrent oral ulcers
Ulcers are small with yellow floor surrounded by an erythematous halo aphthous ulcers.
Tender nodules on skin  → Erythema nodosum.


Diagnosis is Behcet's syndrome.