Final answer:
An allergic reaction caused by mold is typically triggered by inhaling airborne mold spores, not by contact with bacteria or people with allergies, or by inhaling pollen.
Step-by-step explanation:
An allergic reaction caused by mold is most commonly triggered by inhaling airborne spores. These spores are tiny reproductive units released by mold fungi, especially during periods when conditions favor their growth, such as in damp or humid environments.
When inhaled, mold spores can enter the respiratory tract and provoke an immune response in sensitive individuals. Symptoms of a mold allergy can include sneezing, coughing, and difficulty breathing. In certain cases, these reactions can be more intense in those with pre-existing respiratory conditions, such as asthma. Long-term exposure to mold may also have the potential to weaken the immune system.