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
[{'content': 'Presence of epithelial pearls in spinous Layer of epithelium is characteristic of \nSelect and explain. \nA. Carcinoma, B. Pre-cancer, C. Dysplasia, D. Metaplasia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]