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': 'Which of the following about carcinoids is not true  a) 80 % occur in appendix and ileum   b) Most of them metastatise to liver  c) 90 % of them cause carcinoma symptoms  d) They can occur in the lungs \nSelect and explain. \nA. ac, B. bd, C. cd, D. acd', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]