Final answer:
Working a trained and physically fit horse until exhaustion depends on various factors and is not universally acceptable. It is critical to consider the horse's health, weather conditions, and the intensity of the work, ensuring that the horse does not suffer from any negative health consequences due to over-exertion.
Step-by-step explanation:
The question asks if it is acceptable to work a trained and physically fit horse until exhausted. The answer to this question is d) Depends on the horse's mood. While it is important to ensure that a horse is properly exercised and trained, overworking a horse to the point of exhaustion is not only inhumane but can also be detrimental to the horse's health.
Factors such as the horse's current health status, the weather conditions, the intensity of the work, and the individual horse's limits should always be considered. Working a horse until exhaustion could result in injuries, heat stroke, or other serious health issues.
Therefore, it is essential to monitor the horse's response to exercise and provide rest and recovery as needed.