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.

[EX Q]: Question: A student made observations of four rock samples. Which of these observations most likely describes a sedimentary rock? (A) Sample 1 has bands of light and dark crystals. (B) Sample 2 has pink, gray, and white crystals grown together. (C) Sample 3 is made up of one huge, pale pink crystal. (D) Sample 4 is made up of layers of sand grains cemented together.?
[EX A]: describes, sedimentary, rock?

[EX Q]: Question: Electric cars use large batteries, rather than gasoline, for power. This is an example of electric energy being converted into _________. (A) heat energy (B) motion energy (C) light energy (D) chemical energy?
[EX A]: Electric, cars, electric, energy, converted

[EX Q]: Question: A student is investigating changes in the states of matter. The student fills a graduated cylinder with 50 milliliters of packed snow. The graduated cylinder has a mass of 50 grams when empty and 95 grams when filled with the snow. The packed snow changes to liquid water when the snow is put in a warm room. Which statement best describes this process? (A) Cooling causes the snow to melt. (B) Cooling causes the snow to freeze. (C) Heating causes the snow to freeze. (D) Heating causes the snow to melt.?
[EX A]:
changes, matter., snow., snow, changes, liquid, water, warm, room., process?