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: the emission of sulfur dioxide causes acid rain, Fact2: The sulfur dioxide is converted into sulfuric acid., Question: what causes acid rain? (A) gases (B) rainfall (C) Pollution (D) fossil fuels (E) emissions (F) vehicles (G) burning (H) wind
[A]: E


[Q]: Fact1: Molecules of tRNA bring amino acids to the ribosome in the correct sequence., Fact2: Ribosomes are sites of protein synthesis., Question: Molecules of _ initiate protein synthesis (A) Acids (B) nektar (C) sugar (D) tRNA (E) H 2 O (F) three (G) CO 2 (H) HIV
[A]: D


[Q]: Fact1: a mold spore has a negative impact on the respiratory system, Fact2: Major components of the respiratory system are the lungs, trachea, nose, and the cell., Question: What has a negative impact on the lungs? (A) unpolluted air (B) healthy atmosphere (C) mold spore (D) smoking (E) disease (F) influenza (G) clean air (H) A virus
[A]:
C