Which of the following is a corrective action to take for high indoor humidity levels?

Installing a ventilation system is a highly effective corrective action for managing high indoor humidity levels. This option focuses on improving the exchange of indoor and outdoor air, which can help in reducing moisture accumulation. Proper ventilation allows stale, humid air to be expelled from the indoor environment while pulling in drier air from outside, thereby balancing humidity levels.

Ensuring adequate ventilation can significantly improve air quality and reduce the risk of mold growth, as stagnant, humid air creates a conducive environment for mold and other indoor air quality problems. A well-designed ventilation system can effectively control humidity levels, particularly in spaces that generate a lot of moisture, such as kitchens and bathrooms.

In addition, other methods like using air conditioning can contribute to controlling humidity, but ventilation systems specifically target the incoming and outgoing air exchange, making them a more specialized solution for humidity control.