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: Radiology
Earliest radiological finding of chron's disease 
Select and explain. 
A. Coable stone appearance, B. Raspberry appearance, C. Aphthous lesions, D. String sign of kantor
C: Aphthous lesions
Answer: C: Aphthous lesions 
Explanation: Earliest change are aphthous lesions or erosions.