Which type of firearm typically requires both hands to operate effectively, usually held against the shoulder?

The correct answer is a rifle, which usually requires both hands for effective operation and is typically designed to be held against the shoulder. This method allows for better stability and accuracy when aiming and firing, as the rifle's longer barrel enhances precision over greater distances. Holding the rifle against the shoulder also helps to absorb recoil, making it easier to control the firearm during and after discharge.

In contrast, while a shotgun can also be shouldered and may require two hands for operation, it is primarily recognized for its short-range impact and is often used in different contexts from a rifle. A pistol, on the other hand, is designed for one-handed operation, making it less stable when aimed with two hands compared to a rifle. Lastly, a submachine gun is typically fired with two hands as well, but it is designed for close-quarters combat and rapid-fire engagements rather than the long-range accuracy that a rifle provides. Thus, while there are similarities among the different types of firearms, the characteristics and intended uses of a rifle distinctly confirm it as the choice that requires both hands to operate effectively when shouldered.