instruction:
In this task, you need to answer basic science questions. For each question, several terms are intentionally masked with ***. This masking can cover very few or many of the question words. Clearly, if masked terms are important, the modified question will be impossible to answer. Please indicate the correct answer with one of the following responses: "A", "B", "C", "D" or "E". While "A"-"D" correspond to the answer options provided in the input, "E" represents "I don't know" for questions that do not provide enough information. Respond via "E" if the question is not answerable. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D', 'E'.
question:
Question: James and Jordan roll their cars across the *** living room ***. They notice that they are not moving as fast as they had when they played on the *** kitchen ***. Which *** is responsible for slowing down the cars?  (A) Wind (B) Gravity (C) Thrust (D) Frictio.
answer:
D.


question:
Question: *** *** battery-powered flashlight *** turned ****** electrical energy *** transformed ***  (A) light energy. (B) heat energy. (C) chemical energy. (D) energy of motion.
answer:
A.


question:
Question: A *** *** that an *** *** *** *** when it is *** by a ***. Which *** *** the *** of the *** as a *** of this ***?  (A) The mass of the balloon increases because the size of the balloon has increased. (B) The mass of the balloon increases because the temperature of the balloon has increased. (C) The mass of the balloon stays the same because the gas inside the balloon still has the same mass after it warms up. (D) The mass of the balloon stays the same because warming decreases the mass enough to cancel out the effect of increasing the size.
answer:

E.