This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Drowning, Subject name: Forensic Medicine
[{'content': 'In deaths due to scuba diving, All of the following investigations done before, during and after autopsy is of more value except \nSelect and explain. \nA. Diatom test, B. X - ray chest, C. X - ray knee joint, D. Gas chromatography', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Investigations in SCUBA diving fatalities : Radiological examination: X-ray of chest in standing position will indicate a fluid level in chest cavity or presence of pneumothorax or pneumomediastinum. Radiographs of knees will show nitrogen bubbles in the joint, indicating a long diving period. In case of air embolism, air samples should be removed with a syringe lubricated by oil for gaschromatography and electron mass spectrometer analysis of gas components. >95% nitrogen indicates nitrogen narcosis. Diatoms test is a test used for detecting antemoem drowning, Not scuba diving.', 'role': 'assistant'}]