instruction:
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:
Question: If 10 grams of water are added to 5 grams of salt, how much salt water will be made? (A) 2 grams (B) 5 grams (C) 10 grams (D) 15 grams?
answer:
10, grams, water, 5, grams, salt, water


question:
Question: A student walks across a carpeted floor. When she touches a doorknob she sees a spark and feels a shock. Which force is responsible for the spark and shock? (A) Electrical (B) Friction (C) Gravitational (D) Magnetic?
answer:
walks, carpeted, floor., touches, doorknob, sees, spark, shock., force


question:
Question: How do plants most commonly break large rocks into smaller pieces? (A) Plant leaves insulate surrounding rocks from extreme temperatures. (B) Plant roots grow into cracks in rocks. (C) Seeds from plants fall onto rocks and release acidic compounds. (D) Stems of plants surround and squeeze rocks.?
answer:

plants, break, large, rocks