Answer:
b. Biological pollutants.
Step-by-step explanation:
Fungal spores, bacterial and animal dander are examples of biological pollutants. These are substances in the indoor environment that originate from living organisms and can have harmful effects on human health. Other examples of biological pollutants include pollen, dust mites, viruses, and bacteria.
These pollutants can cause allergic reactions, respiratory problems, and other health issues. To reduce exposure to biological pollutants, it is important to maintain good indoor air quality by controlling humidity levels, using air filters, and ensuring proper ventilation. Regular cleaning, including dusting and vacuuming, can also help reduce levels of biological pollutants in the indoor environment.