Final answer:
A food allergy is an immune response to a normally harmless food substance, distinct from food intolerance, and is classified as an immediate hypersensitivity. Allergies can have genetic predispositions and often present more frequently in children. The correct answer is options A.
Step-by-step explanation:
A food allergy is an unusual sensitivity to a normally harmless food substance that causes an immune system reaction in a person's body. The correct answer to the question is A) Food Allergy. Unlike food intolerances, which involve the digestive system's inability to break down certain foods, a food allergy involves an immune system response. Specifically, in an allergy, a person's immune system reacts to a harmless protein from the environment, causing unpleasant symptoms.
Allergies can cause a range of symptoms and are often more common in children. Allergens that cause food allergies act as antigens, triggering an immune response even though they are not typically harmful to the body. This type of hypersensitive immune response is known as a type I hypersensitivity.
When referring to the immune system not normally mounting a response to the molecules in food, the term is immune tolerance. And an allergy to pollen is classified as an immediate hypersensitivity.