This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Medicine
[{'content': 'For FITTER the shortest needle length in Pens should be....... mm? \nSelect and explain. \nA. 4, B. 5, C. 6, D. 8', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. 4FITTER a congress which made new guidelines to help people on injections & pumps in Diabetes. We should use the shortest needle size (4mm for pens & 6mm for syringes].', 'role': 'assistant'}]