Type I Hypersensitivity reactions are triggered by antigen binding to IgE receptors on mast cells or basophils. A recognized example of type I reaction is

Correct Answer: C

Rationale: Allergic asthma is a classic example of type I hypersensitivity, which involves IgE-mediated mast cell degranulation.

Correct Answer: A

Rationale: A family history of allergic diseases significantly increases the risk of allergic rhinitis. Genetic predisposition plays a major role, while the other listed factors do not have a strong association with allergic rhinitis.

Correct Answer: D

Rationale: Allergic reactions are unpredictable and not dose-dependent, unlike drug toxicity and interactions.

Correct Answer: B

Rationale: Bone marrow transplantation is a definitive treatment for severe aplastic anemia.

Correct Answer: B

Rationale: Vaccination does not amplify anaphylaxis, while infections, stress, and physical activity can increase susceptibility.