What should protect exterior openings of air intakes and exhausts?

The correct choice involves using a screen, louvers, or grille to protect exterior openings of air intakes and exhausts. This approach is crucial for several reasons.

Firstly, screens provide a barrier against insects, debris, and larger particles, which helps maintain the efficiency of the ventilation system by preventing blockages. Louvers, on the other hand, can control airflow direction and reduce rain or snow from entering while still allowing necessary air exchange, which is vital for residential and commercial buildings. Grilles can also serve a similar function, offering a finish that allows air to flow while maintaining protection against outside contaminants.

Using screens, louvers, or grilles is a practical solution that balances functionality with the protection of the air intake and exhaust systems, ensuring they operate efficiently while safeguarding against potential hazards from the environment. Other options like plastic covers, metal plates, or wooden shutters would not offer the same level of airflow control or protection while allowing for proper ventilation.