For health and safety reasons, the state association's weight-control program shall require:

The correct choice is hydration testing, which plays an essential role in ensuring the health and safety of wrestlers. Proper hydration is critical for athlete performance and well-being, especially in a sport like wrestling where weight management can lead to dehydration. Implementing hydration testing helps to monitor and maintain safe fluid levels, which can prevent serious conditions such as heat-related illnesses and promote recovery.

By prioritizing hydration, the program supports athletes to compete effectively while safeguarding their physical health. Monitoring hydration also aligns with the overall goal of promoting safe practices in sports, ensuring that wrestlers are not only maintaining weight but also following strategies that preserve their overall condition and endurance.

The other choices, while relevant to weight management, do not encompass the complete scope of health and safety requirements as directly related to immediate physical conditions as hydration testing does. Therefore, hydration testing stands out as the most crucial requirement for safeguarding the participants' health in the context of weight control.