You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
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: *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***.  (A) dissolving (B) deposition (C) weathering (D) erosion.
Solution: E.
Why? All the words are dropped, so the correct answer should be 'E' that stands for "I don't know".

New input: Question: *** ***. *** is part of a *** *** that slowly *** on *** where __________.  (A) continental plates collided (B) oceanic plates pulled apart (C) a continental and an oceanic plate pulled apart (D) a continental and an oceanic plate collide.
Solution:
E.