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': 'Cavo surface angle for amalgam restoration is butt joint as: \nSelect and explain. \nA. It increass compressive and tensile strengths, B. Decreased compressive, increased strength, C. Decreased compressive, decrease tensile strength, D. Increased compressive, increased tensile strength', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]