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: Medicine
[{'content': 'The most prevalent esophageal cancer world wide is: \nSelect and explain. \nA. Squamous cell ca, B. Adenocarcinoma, C. Sarcoma, D. Adenoid cystic carcinoma', 'role': 'user'}, {'content': "Answer: A \nExplanation: Answer is A (Squamous cell Ca): `By far the most common esophageal cancer world wide is squamous cell carcinoma' - Current Gastroenterology 'Over the past few decades there has been a progressive increase in the incidence of adenocarcinoma of the distal esophagus so that it accounts for more than 50% of all new cases of esophageal cancer. Squamous cell carcinoma is still the most common type world wide' - CSDT/469 Confusing inference Most prevalent esophageal cancer world wide (old + new cases) is Squamous cell ca Most common esophageal cancer world wide (new cases) is Adenocarcinoma", 'role': 'assistant'}]