The protective mask will not protect against which type of gases?

The reason that the specified answer is correct is that the protective mask is designed to filter and protect against many hazardous substances, but it has limitations when it comes to certain gases. Carbon monoxide is a colorless, odorless gas that can be harmful or fatal even in low concentrations, and the protective mask does not effectively filter this gas because it primarily requires a different method for detection and protection, such as proper ventilation or specialized equipment.

Ammonia vapors can typically be filtered by certain types of protective masks, but carbon monoxide's unique properties make it particularly dangerous and not adequately addressed by standard masks. Together, these gases represent a risk that the protective mask is not equipped to handle effectively.

The other options include gases and particulates that the protective mask is designed to address to varying degrees. Chlorine gas and ammonia vapors can be filtered to some extent, while dust and smoke are managed by the mask's particulate filtering capabilities. Hydrogen sulfide, while toxic, may still have some level of filtration under specific conditions. Therefore, the mask's limitations are most evident regarding carbon monoxide and its handling.