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.

Input: Consider Input: Question: A student discovers his two-week-old lunch in the back of his locker. What kind of organism may have been eating it while it was lost? (A) Decomposer (B) Predator (C) Prey (D) Herbivore?

Output: student, two-week-old, lunch, organism, eating


Input: Consider Input: Question: A company that makes fences started using a new material instead of wood. The new material will last longer than wood. What is the most likely benefit of the new material? (A) The new material will keep people safe. (B) The new material will keep pets contained. (C) The new material can make a yard attractive. (D) The new material can save money on replacements.?

Output: material, last, longer, benefit


Input: Consider Input: Question: A simple way to describe forces is to say that they are ___. (A) light and dark (B) pushes and pulls (C) mechanical and electrical (D) chemical and physical?


Output: describe, forces