Which of the following best describes the method of operation for a Marine Corps Rifle Squad?

The method of operation for a Marine Corps Rifle Squad is best described by repelling enemy assaults by fire and close combat. This reflects the fundamental tactics employed by a rifle squad in combat situations. The squad is typically composed of a small, cohesive unit trained to engage the enemy effectively through a combination of direct fire, maneuvering, and using the environment to their advantage.

Marine Corps squads operate with an emphasis on teamwork and combined arms tactics. They are trained to deliver suppressive fire while maneuvering to close with the enemy, thereby overwhelming them through coordinated fire and assault techniques. This tactical approach is essential for maintaining combat effectiveness on the battlefield and responding to various threats.

The other options do not accurately capture the primary function of a rifle squad. Isolated missions do not reflect the team's interdependence in combat. Coordinating directly with naval units only pertains to specific operational contexts but is not the general tactic of the squad. Training local forces, while important, is a separate function typically undertaken by different units, rather than a direct operational method for a rifle squad in combat situations.