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.

Example Input: Question: Trevor takes his radio to the beach. He uses batteries to supply energy. The energy transformation occurring is ___. (A) sound to heat and chemical (B) electrical to chemical and some heat (C) chemical to heat with a small amount of sound (D) chemical to sound and some heat?
Example Output: batteries, energy., energy, transformation

Example Input: Question: During winter months, Amina sometimes notices ice covering the hoods of parked cars. Once the engine of the car runs for a while, the ice on the hood begins to melt. What form of energy is released from the car engine to melt the ice? (A) chemical (B) electrical (C) heat (D) light?
Example Output: ice, melt., energy, released, car, engine, melt, ice?

Example Input: Question: Hydrochloric acid is added to a beaker containing a piece of zinc. As a result, zinc chloride is formed and hydrogen gas is released. This is an example of (1) a chemical reaction (2) a physical change (3) photosynthesis (4) evaporation?
Example Output:
Hydrochloric, acid, added, piece, zinc., zinc, chloride, formed, hydrogen, released., example