This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vermiform Appendix, Subject name: Surgery
[{'content': 'Earliest symptom in acute appendicitis is: \nSelect and explain. \nA. Pain, B. Fever, C. Vomiting, D. Rise of pulse rate', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans: a (Pain)Ref: Bailey & Love, 24th ed, p. 1206 & 23rd ed, p. 1080', 'role': 'assistant'}]