What describes an average backup according to the presentation?

The description of an average backup as a horse that is straight and quiet with light contact emphasizes the importance of balance, control, and responsiveness in equine movement. In a proper backup, the horse should maintain a straight posture, indicating alignment and the ability to move backward without veering off course. The term "quiet" suggests that the horse is relaxed and calm, which is crucial for effective communication between the horse and the handler. Light contact refers to having a soft but consistent connection with the reins, allowing for subtle guidance without causing tension or resistance in the horse.

This understanding is pivotal, as it reflects the ideal state of cooperation between the horse and handler during this maneuver. The other options describe scenarios that deviate from this ideal, such as excessive energy or resistance, which indicate lack of control or understanding from the horse. Therefore, recognizing that an average backup is characterized by control and composure allows for proper training and execution as part of equine science knowledge.