Which of the following is NOT a type of patrol?

The correct answer is that "Observer" is not recognized as a standard type of patrol in military terminology. In military operations, different types of patrols serve specific purposes, all of which are essential for gathering intelligence, conducting reconnaissance, or engaging in combat activities.

Combat patrols are geared towards engaging the enemy, often involving direct action to disrupt or destroy enemy forces. Tracking patrols focus on following the movements of enemy forces or identifying their activities based on evidence left behind. Recon patrols aim to gather information on enemy locations, strengths, and activities without direct engagement, often operating in enemy territory to observe and report back on what they find.

In contrast, the term "observer" does not refer to a distinct type of patrol but rather can describe a role or function within various operations. While an observer may be involved in patrols, the designation itself does not categorize a specific method or mission associated with patrol operations.