You are given a science question (easy-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

Input: Consider Input: A scientist combines oxygen and hydrogen to form water. This combination illustrates that water is
(A) an atom. (B) an element. (C) a mixture. (D) a compound.

Output: D

Input: Consider Input: Sal is looking at a map of Massachusetts. He has measured the distance, in inches, from Boston to Salem on the map. He wants to know how many actual miles the inches represent. What feature of the map should he look for?
(A) key (B) scale (C) legend (D) compass

Output: B

Input: Consider Input: A dung beetle is an insect that gathers waste from animals, rolls it into a compact ball, lays eggs in it, and buries it in the soil. This gives the eggs a warm, safe place to hatch and provides a food source for the developing larvae. Which impact does the dung beetle most likely have on its ecosystem?
(A) It helps return nutrients to the soil. (B) It makes animal waste harder to degrade. (C) It causes an unhealthy accumulation of animal waste. (D) It depletes nutrients from the soil to benefit its young.
Output: A