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: melting is when solids are heated above their melting point, Fact2: Ice cubes melt in liquid water., Question: What, when heated, turns into liquid water? (A) gasoline (B) oil (C) a solute (D) fire (E) ice cubes (F) a prism (G) mussels (H) Energy.
[A]: E

[Q]: Fact1: Pneumonia may be caused by an infection or injury of the lungs., Fact2: Lung injuries are treated with bronchodilatory treatment., Question: What treatment can be used in treating pneumonia? (A) the respiratory system (B) a breathing mask (C) bronchodilatory treatment (D) aqueous solution (E) immunotherapy (F) radiation therapy (G) immune system (H) chemotherapy
[A]: C

[Q]: Fact1: Roundworms make up the phylum Nematoda., Fact2: Also, nematoda and rotifera are important groups contributing to soils., Question: Where are roundworms useful in an ecosystem? (A) killing animals (B) soils (C) fields (D) bacteria (E) eating plants (F) wetland (G) food (H) alveoli
[A]:
B