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': 'Localised shrinkage porosity increases by \nSelect and explain. \nA. Increase in sprue length, B. Increase in sprue diameter, C. Increase in mold temperature, D. Increase in melt temperature', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]