You are given a science question (easy-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

Input: Consider Input: Many things can contribute to the development of a theory. A student made a list of some things that might help scientists develop a theory. Observations Calculations Conversations Publications From the student's list, which must be used in the development of every theory?  
 (A) Observations (B) Conversations (C) Publications and calculations (D) Calculations and conversations

Output: A


Input: Consider Input: Some pea plants always have peas with smooth skin. Other pea plants always have peas with wrinkled skin. How can a student best predict which kind of pea will grow from a seed that is planted?  
 (A) by checking the amount of water in the soil (B) by checking how often the pea plant receives sunlight (C) by checking how much space the plant will have to grow (D) by checking the type of peas growing on the parent plants

Output: D


Input: Consider Input: Scientists determined that cabbages grown using Fertilizer A grew bigger than cabbages grown using Fertilizer B or no fertilizer at all. The scientists repeated the investigation and produced the same results. Which best explains the purpose of repeating this investigation?  
 (A) to ensure that the cabbages are safe for human consumption (B) to discover the scientific principle that causes the increased growth (C) to confirm that the observed differences were caused by the fertilizer (D) to determine the difference between the experimental and control groups


Output: C