question: What is the cause of common mold allergies?
distractor3: viruses
distractor1: immobile mold spores
distractor2: bacteria
correct_answer: airborne mold spores
support: Mold allergies are very common. They are caused by airborne mold spores. When the spores enter the respiratory tract, the immune system responds to them as though they were harmful microbes. Symptoms may include sneezing, coughing, and difficulty breathing. The symptoms are likely to be more severe in people with asthma or other respiratory diseases. Long-term exposure to mold spores may also weaken the immune system.