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: Which sense can be used to determine an object's ability to reflect light? (A) sight (B) hearing (C) smell (D) taste?

Output: sense, determine, ability, reflect, light?


Input: Consider Input: Question: Moving water was the most important factor in forming which of these? (A) the Grand Canyon (B) San Andreas Fault (C) the Rocky Mountains (D) Mount St. Helens Volcano?

Output: Moving, water, important, factor, forming


Input: Consider Input: Question: Dominic placed a caterpillar in a container with different kinds of leaves. Which information should he record to find out what food this caterpillar eats? (A) the type of leaves the caterpillar has eaten (B) the amount of time for all the leaves to be eaten (C) the number of leaves that were put in the container (D) the number of minutes the caterpillar spends eating?


Output: caterpillar, container, leaves., information, record, food, eats?