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'.

Ex Input:
Question: A simple machine that helps move a flag up a flagpole is  (A) a bar magnet (B) an inclined plane (C) a pulley (D) a leve.

Ex Output:
C.


Ex Input:
Question: A girl signals her friend by shining a flashlight on a mirror. Her friend can see the signal because  (A) heat energy can be transferred from one object to another (B) mechanical energy can be transferred from one object to another (C) sound energy can be reflected from one object to another (D) light energy can be reflected from one object to anothe.

Ex Output:
D.


Ex Input:
Question: Kyle designed an *** to see if the number of *** increased in the soil next to his house. How should he begin his investigation?  (A) Count the number of earthworms that are already there (B) Make sure that there are no other organisms located in the soil (C) Clean out the plants in the garden (D) Make sure that the soil is mois.

Ex Output:

E.