Final answer:
The events lasting 1-4 hours would have environmental factors playing the largest role in determining performance.
Step-by-step explanation:
Out of the given options, the events lasting 1-4 hours would have environmental factors playing the largest role in determining performance. This is because longer durations of exercise, such as endurance activities, are more likely to be affected by external factors such as temperature, humidity, and terrain. For example, in a marathon race, the weather conditions and course difficulty can greatly impact a runner's performance.