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: Surgery
[{'content': 'To control pain in long standing cancer cases, the recommended route of administration is: \nSelect and explain. \nA. i.v, B. Subcutaneous, C. Sublingual, D. Oral', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Oral route is the preferred route for administration of analgesics in cancer patients, even for long standing pain due to ease of dosing, reliability and convenience.', 'role': 'assistant'}]