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.

[EX Q]: Question: Scientists invented a liquid that removes grease and keeps the skin soft. How could this discovery most likely be used? (A) to improve dish soap (B) to cure a disease (C) to make clothes (D) to grow plants?
[EX A]: liquid, removes, grease, skin, soft., used?

[EX Q]: Question: Rocks and minerals are common materials found on Earth. Which property do most rocks and minerals share? (A) They are pure. (B) They are solid. (C) They are liquid. (D) They are magnetic.?
[EX A]: property, rocks, minerals, share?

[EX Q]: Question: Four solid balls, each with a different mass, are moving at the same speed. Which ball would require the most force to stop its motion? (A) ball with a mass of 5 kg (B) ball with a mass of 10 kg (C) ball with a mass of 15 kg (D) ball with a mass of 20 kg?
[EX A]:
different, speed., ball, require, force, stop, motion?