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': 'Suckback porosity in the casting can be eliminated by: \nSelect and explain. \nA. Increasing the mold metal temperature difference, B. Increasing the flow of molten metal, C. Flaring the point of the sprue attachment, D. None of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Flaring of the sprue former may act in much the same way as a reservoir, facilitating the entry of the fluid alloy into the pattern area.\xa0\nIf possible, the sprue former should be attached to the portions of the pattern with the largest cross-sectional areas.\xa0\nIt is best for the molten alloy to flow from a thick section to surrounding thin areas (e.g., the margins) rather than the reverse.\xa0\nThis design minimizes the risk of turbulence. Also, the orientation of the sprue former should minimize the risk for metal flow onto flat areas of the investment or onto small areas such as line angles.\n\nReference: PHILLIPS’ SCIENCE OF DENTAL MATERIALS, 12th ed page no 214', 'role': 'assistant'}]