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: A student is investigating which type of soil is best for growing tomato plants from seeds. The student plants four tomato seeds in each of three different containers of soil. Which step of the procedure would help the student get the most reliable results?  
 (A) Place one container in a dark room. (B) Use different types of tomato seeds. (C) Change only the soil type in each container. (D) Water each container with a different amount of water.

Output: C


Input: Consider Input: Which type of organism is the best at fixing nitrogen?  
 (A) bacteria (B) fungi (C) protists (D) animals

Output: A


Input: Consider Input: Nevada is much drier than regions in California that are at the same latitude. Compared to these regions in California, which feature of Nevada contributes most to this dry climate?  
 (A) mountain ranges to the west (B) high mean elevation (C) frequent earthquakes (D) soil with a high sand content


Output: A