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").

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
B

Fact1: volcanic ash in the atmosphere decreases the temperature by blocking the sun, Fact2: Supersaturation is inferred to be a common state for atmospheric haze particles., Question: What decreases the temperature by blocking the Sun? (A) cilia (B) the Sun (C) the wind (D) haze (E) ice (F) fat (G) rain (H) acids
D

Fact1: sonar is used to find the location of an object, Fact2: Dolphins have an astonishing sonar capability., Question: What can find the location of an object? (A) observe it (B) sea squirts (C) animals (D) Jellyfish (E) radiography (F) Light (G) satellites (H) dolphins
H