This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
[{'content': 'During the Window period of patient with AIDS - \nSelect and explain. \nA. ELISA is -ve, B. Western Blot is -ve, C. Both are -ve, D. PCR is -ve', 'role': 'user'}, {'content': 'Answer: C \nExplanation: sero negative infective stage is known as the window period REF:ANANTHANARAYANAN TEXT BOOK OF MICROBIOLOGY 9EDITION PGNO.579', 'role': 'assistant'}]