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': 'Presence of spiral grooves in the barrel of weapon is referred to as \nSelect and explain. \nA. Rifling, B. Incendiary, C. Cocking, D. None of the above', 'role': 'user'}, {'content': "Answer: A \nExplanation: RIFLED GUN RIFLING: Interior of bore has spiral grooves which run parallel to each other, but twisted spirally from breech to muzzle end. These grooves are called 'rifling' Impas Spinning motion to the bullet Greater power of penetration Straight trajectory Increases accuracy & range Paradox gun: A smooth bore gun with small terminal pa rifled.", 'role': 'assistant'}]