Question

question 2
all of the following statements are true of allergens except:
synthetic chemicals may trigger allergic reactions.
asthma can be triggered by allergies.
allergens trigger an immune response when one is not necessary.
everyone is affected by an allergen at a high enough dose.
a persons response to an allergen does not necessarily correlate with the degree of exposure.

Explanation:

Allergens are substances that cause an immune response in allergic individuals. Synthetic chemicals can be allergens. Allergies can trigger asthma. Allergens cause an unnecessary immune response. A person's allergic response isn't always directly related to exposure degree. However, not everyone is affected by an allergen even at high doses; only those with an allergic predisposition are.

Answer:

Everyone is affected by an allergen at a high enough dose.