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: *** system *** responsible *** getting rid *** chemical waste *** water?  (A) digestive (B) urinary (C) locomotion (D) circulator.

SOLUTION: B.

PROBLEM: Question: When an ice cube melts, its state of matter changes from a  (A) gas to a liquid (B) solid to a liquid (C) liquid to a solid (D) solid to a gas.

SOLUTION: B.

PROBLEM: Question: *** trait *** *** tiger inherit *** *** parents?  (A) Choice of mate (B) Hunting skills (C) Personality traits (D) Fur colo.

SOLUTION:
D.