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: If water gets into the crack of a rock and then freezes, the rock will MOST likely (A) break apart (B) be able to float (C) become larger (D) change colors?

Output: water, crack, rock


Input: Consider Input: Question: Which of these converts electrical energy to light energy? (A) a star (B) a flashlight (C) a campfire (D) a tea kettle?

Output: converts, electrical, energy, light, energy?


Input: Consider Input: Question: A shallow container of salt water is placed in sunlight for a day. Which is the most likely result? (A) All of the mixture will evaporate. (B) The salt will keep the water from evaporating. (C) The salt will separate from the water and float at the top of the container. (D) Only the water will evaporate and the salt will remain in the container.?


Output: salt, water, sunlight, day., result?