Rifling patterns on a bullet can assist in determining the type of firearm . What is the MAIN purpose of rifling on a firearm? a adding torque b accelerating speed c controlling trajectory d improving accuracy

The main purpose of rifling on a firearm is to improve accuracy. Rifling refers to the spiral grooves cut into the barrel of a firearm. These grooves cause the bullet to spin as it travels through the barrel, which stabilizes the bullet's flight and improves its accuracy. Therefore, the correct answer is:<br /><br />d. improving accuracy