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 Q]: Fact1: Biomass is the total mass of organisms at a trophic level., Fact2: Each stage is a trophic level., Question: The total mass of organisms in an environmental stage is called what? (A) food pyramid (B) extinction (C) ecological pyramid (D) food chain (E) vegetation (F) food (G) ligt (H) biomass
[EX A]: H

[EX Q]: Fact1: Urine is the liquid waste product of the body that is excreted by the urinary system., Fact2: Mammals excrete urea in the watery form of urine ., Question: What is a waste product of the body that is excreted by the urinary system? (A) potash (B) food (C) CO 2 (D) sugar (E) urea (F) liquid (G) H 2 O (H) sulfur
[EX A]: E

[EX Q]: Fact1: Kidney failure may be treated with dialysis., Fact2: Dialysis Dialysis is a way of cleaning the blood with an artificial kidney., Question: What body fluid does dialysis clean? (A) lymph (B) liquids (C) tissue (D) life (E) Saliva (F) Kidney (G) Blood (H) Fluid
[EX A]:
G