Which weapons are considered organic to the Marine rifle squad?

The Marine rifle squad typically has a defined set of organic weapons that are standard issue and integral to squad operations. The correct choice identifies the M16A2 rifle, M203 grenade launcher, and the M-7 bayonet as being organic to the squad.

The M16A2 rifle serves as the primary firearm for most squad members, providing a reliable and versatile platform for firepower. The M203 grenade launcher is an attachment that enhances the squad's capability to deliver indirect fire and engage targets at greater distances with explosive grenades. The M-7 bayonet, intended for close combat, further complements the squad's weapons, providing a melee option when necessary.

In comparison, other weapon systems listed in the other options are either not standard equipment for a rifle squad or may belong to different units or roles within the Marine Corps. Thus, the correct choice reflects a comprehensive understanding of the organic weapon capabilities tailored for direct infantry operations within the squad structure.