What is considered the estimate of terrain?

The correct response identifies the components used to assess terrain in a military context. Key terrain refers to geographic features that can provide an advantage to forces that control them. Obstacles are features that impede movement, and cover and concealment are critical for protecting personnel and equipment from detection and enemy fire. Finally, observation and fields of fire are essential for understanding how terrain can be utilized for effective surveillance and engagement of targets.

This choice organizes these elements in a way that highlights their relevance to military planning and operations, emphasizing how terrain affects a unit's ability to maneuver and react during combat. Each component plays a vital role in situational awareness and tactical decision-making, which are crucial in ensuring success in battlefield scenarios.