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'.

Example Input: Question: A *** can *** a serious disease. When a *** *** is developed, it is given to a *** *** of people. Why would it be *** to *** each *** on a *** *** of *** *** every*** can have one?  (A) to figure out how much the vaccine is worth (B) to determine how the vaccine will affect people (C) to understand how that disease affects the human body (D) to find out how many people are affected by the diseas.
Example Output: B.

Example Input: Question: A *** is modeling the *** between a *** *** and a *** organism. Which *** is a *** of a *** organism?  (A) a student passing out water to a group (B) a student getting cereal from the cabinet (C) two students collecting trash from a group (D) four students working together to move a des.
Example Output: E.

Example Input: Question: *** *** plants *** *** break large rocks *** smaller ***?  (A) Plant leaves insulate surrounding rocks from extreme temperatures. (B) Plant roots grow into cracks in rocks. (C) Seeds from plants fall onto rocks and release acidic compounds. (D) Stems of plants surround and squeeze rocks.
Example Output:
B.