This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ballistics, Subject name: Forensic Medicine
[{'content': 'Primary and secondary markings over metal bullet help in? \nSelect and explain. \nA. Identification of weapon, B. Identification of wound, C. Identification of person, D. Severity of tissue damage', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Markings on the bullet are used to identify the gun used. Bullet finger printing -Study of comparison of markings on crime bullet & test bullet under comparison microscope Primary Marking/Class Characteristics: Produced by rifling groovesQ * Primary markings are used to identify the make & model of the guns involved. Secondary markings or individual/accidental characteristics Produced by irregularities by manufacturing process are different for each gun produced by same manufacturer. They are useful in identifying the specific gun which was fired.', 'role': 'assistant'}]