In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").
Q: Fact1: Lymphocytes are the key cells involved in the immune response., Fact2: Allergies are an immune system response., Question: Lymphocytes are a key cell involved in what type of reaction? (A) Final Symphonic movement (B) illness (C) positive (D) fever (E) allergic (F) autologous transplant (G) allogenic stem cell transplant (H) sweating
A:
E