TASK DEFINITION: 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'.
PROBLEM: Question: An ice cube is placed in a pan. The pan is placed over an open flame. Which change will most likely happen over time?  (A) The ice changes to a liquid and back to a solid. (B) The ice changes to a liquid then to a gas. (C) The ice changes to a gas and back to a solid. (D) The ice changes to a gas then to a liquid.

SOLUTION: B.

PROBLEM: Question: Which of the *** would *** in a *** in the *** *** *** in the ***?  (A) An increase in the amount of grass (B) An increase in the fish population (C) A decrease in the fish population (D) A decrease in the human populatio.

SOLUTION: E.

PROBLEM: Question: *** *** *** difference *** *** food chain *** *** food web?  (A) A food chain always ends with a primary consumer. (B) A food web is made up of many food chains. (C) A food web only shows one flow of energy through the ecosystem. (D) A food chain is made up of many food webs.

SOLUTION:
B.