Which of the following explain why players are advised NOT to stay in a steam room for longer than 15 minutes?

Here are the answers to your questions:

The human body cools itself primarily through the evaporation of sweat. In a steam room, the temperature is high ($41^\circ\text{C}$), which causes the body to sweat. However, the humidity is also very high (80% to 100%), meaning the air is already saturated with water vapor. This high humidity significantly reduces the rate at which sweat can evaporate from the skin. When sweat cannot evaporate, the body cannot effectively release heat, leading to an increase in core body temperature and thus, overheating.
The correct option is A.