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': 'Green shrinkage seen in \nSelect and explain. \nA. Phosphate bonded investment., B. Ethyl silicate bonded investment., C. Gypsum bonded investment., D. All of the above.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: • Green shrinkage:\n-Occurs during heating of silicate investments.\n-Occurs due to loss of alcohol & water during phase(168ºC) to form a concentrated, hard gel.\nThis also leads to volumetric contraction of the mould', 'role': 'assistant'}]