An FAS score of 5 in horses may include which of the following behaviors?

An FAS score of 5 indicates a higher level of fear or stress in horses and is characterized by behaviors that reflect significant agitation or distress. Striking is an example of such behavior, as it involves aggressive actions that can be a direct response to fear or anxiety. This kind of behavior signifies that the horse is in a heightened state of arousal and is likely attempting to defend itself or escape from a perceived threat.

In contrast, calm responses, listening quietly, and standing still reflect a calmer emotional state, which would be more characteristic of lower FAS scores. Horses demonstrating these behaviors are typically exhibiting signs of relaxation and comfort rather than fear or distress. Thus, the behaviors associated with a higher FAS score correlate directly with signs of agitation, making striking the appropriate choice for this scenario.