You are given an elementary science question along with a few answer options. List all the words from the question that are essential and sufficient for choosing the correct answer option. Keep in mind that essential words are necessary to understand the meaning of the given question. However, non-essential words provide little information needed to select the correct answer. You can think about it like this: If the question was in another language, knowing the meaning of which words were necessary and enough for you to understand the question and answer it?. If your answer consists of multiple spans of words from the question, separate those using a comma (", "). Do not generate any word that is not present in the question. Make sure that your response is contained in the given question and the words are in the same order as the question.
 Grammatical correctness is not important.

Question: You have three different boxes of cereal that claim to contain 400 g each. To check if this information is true, you use a ___. (A) triple beam balance (B) ruler (C) compass (D) scale?
three, boxes, cereal, contain, 400, g, check

Question: Plants on hills keep dirt in place during a rain storm. Plant roots grow into the dirt and keep the dirt from moving. Why do roots grow into the dirt? (A) to release gases (B) to release water (C) to absorb energy (D) to absorb nutrients?
roots, grow, dirt?

Question: Matt had two types of dog food and gave his dog both types of food at the same time every day. He recorded his observations. What question is best answered by this experiment? (A) What time of day does Matt's dog eat the most? (B) What dog food is of better quality? (C) How quickly does Matt's dog eat? (D) What type of food does Matt's dog prefer?

two, types, dog, food, dog, food, every, day., question, answered