This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Skeletal system, Subject name: Radiology
[{'content': 'A person has an injury in the forefinger with glass and it is suspected that he has a retained piece of glass in his finger. Which is the first investigation you will do? \nSelect and explain. \nA. Plane radiograph, B. Ultrasound, C. CT scan, D. MRI', 'role': 'user'}, {'content': 'Answer: A \nExplanation: All glass, regardless of type or lead content, is radiopaque and should be visible on a properly exposed and positioned radiograph. Hence the answer would be Plain radiograph', 'role': 'assistant'}]