Final answer:
The correct statement regarding the effects of fatigue is that it slows reaction time and contributes to errors, making it a serious risk for activities requiring constant vigilance like driving.
Step-by-step explanation:
The statement that best describes the effects of fatigue is d) Fatigue slows reaction time and contributes to errors. When a person is fatigued, their brain and nervous system begin to function more slowly, leading to slower reflexes and less clear thinking. Additionally, fatigue can result in decreased mental alertness, compromised cognitive function, and an increased risk for errors. It is particularly dangerous in activities requiring constant attention, such as driving or operating machinery, as fatigue can lead to a much higher risk of accidents. Therefore, it is crucial to address fatigue appropriately, ensuring adequate rest and managing stressors effectively.