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: Dental
[{'content': 'A 60 year old male patient wants rehabilitation of missing teeth. Intra-oral examination reveals upper and lower edentulous arches. The casts were mounted using impression plaster. The W/P ratio for this gypsum product is- \nSelect and explain. \nA. 0.50-0.75, B. 0.45-0.50, C. 0.28-0.30, D. 0.22-0.24', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]