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: Surgery
[{'content': 'All the following are true regarding FASTexcept \nSelect and explain. \nA. It is a focused abdominal sonar for trauma, B. It is accurate in detecting <50 ml. of free blood, C. It cannot reliably exclude injury in penetrating trauma, D. It detects free fluid in the abdomen or pericardium', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]