Which of the following is a part of the 3 D's in reconnaissance?

The correct choice, which is a part of the 3 D's in reconnaissance, is "Discovery." In the context of reconnaissance, the 3 D's refer to key components that are essential for effective reconnaissance operations: Detection, Decision, and Discovery.

Discovery specifically focuses on identifying and gathering information about the enemy's positions, strengths, and movements. This is critical for gaining situational awareness and supporting tactical decision-making. In military operations, the ability to discover enemy intent and capabilities can significantly affect the outcome of engagements and overall mission success.

Understanding the role of discovery within reconnaissance helps scouts conduct more thorough assessments of the battlefield, ultimately enhancing operational effectiveness. The other options do not represent recognized elements within the 3 D's framework in reconnaissance, which is why they do not align with the principles needed for effective reconnaissance strategies.