This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thanatology, Subject name: Forensic Medicine
[{'content': 'Colour change in pyrogallol test for air embolism is \nSelect and explain. \nA. Orange to brown, B. Green to yellow, C. Colourless to brown, D. Colourless to pink', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Pyrogallol test : - To detect antemoem air embolism - Gas from the hea on addition to pyrogallol solution will change from colourless to brown in presence of free oxygen', 'role': 'assistant'}]