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").

Ex Input:
Fact1: Active immunity results when an immune response to a pathogen produces memory cells., Fact2: Vaccination is Active Acquired Immunity., Question: What results when an immune response to a pathogen produces memory cells? (A) anemia (B) vaccination (C) kill them (D) competition (E) lie detectors (F) rapid expansion (G) killing insects (H) it needs them

Ex Output:
B

Ex Input:
Fact1: a battery converts chemical energy into electrical energy, Fact2: Electrical energy can be converted into kinetic energy and heat energy by an electric motor., Question: What can convert chemical energy into kinetic energy (A) a magnet (B) a vacuum (C) a windmill (D) a battery (E) arteries (F) barnacles (G) animals (H) engines

Ex Output:
D

Ex Input:
Fact1: a graduated cylinder is used to measure volume of a liquid, Fact2: For test cylinders without graduation marks, a manual calibration method has to be used., Question: graduation markings are used to measure the what of a liquid (A) viscocity (B) size (C) flow (D) volume (E) density (F) smell (G) Decibels (H) tube

Ex Output:
D