Which key battle drill focuses on responding to enemy contact?

The key battle drill that focuses on responding to enemy contact is the one centered around "React to contact." This drill is specifically designed to address immediate actions taken by a unit when they encounter enemy forces unexpectedly. It emphasizes the importance of situational awareness and rapid decision-making in combat scenarios, allowing soldiers to react effectively to adversarial threats.

This drill covers various essential actions, such as taking cover, returning fire, and coordinating with teammates to either maneuver or seek additional support. By mastering the "React to contact" drill, soldiers enhance their ability to confront sudden engagements and maintain operational effectiveness in the face of enemy actions.

In contrast, the other options relate to broader operational strategies or specific missions. "Defense" pertains to maintaining positions against enemy attacks rather than initial contact responses. "Attack" involves planned movements to engage the enemy, while "Gather intelligence" focuses on collecting information about the enemy rather than directly responding to an encounter. Therefore, the specific focus of "React to contact" on immediate engagement makes it the correct answer.