This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infection, Subject name: Medicine
[{'content': 'Definition of PUO includes all of the following except: \nSelect and explain. \nA. Undiagnosed after one week of investigation, B. Immuno compromised status should be ruled out, C. Temperature more than 38.3 C, D. Fever persisting for more than 3 weeks', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. Undiagnosed after one week of investigationUndiagnosed after 1 week of investigation is not included in the latest criteria for PUO.Criteria for diagnosis of PUO:* Fever >38.3-degree C (101F) on 2 occasions* Duration > 3 weeks* No immunocompromised state* Diagnosis not certain after history, physical examination and routine and obligatory investigations.', 'role': 'assistant'}]