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.

Ex Input:
A delta at the mouth of a river is the direct result of  
 (A) runoff from sewage. (B) deposition of sediment. (C) an ancient glacier that passed through. (D) an underground river flowing to the ocean.

Ex Output:
B


Ex Input:
Your community is planning to build a new sanitary landfill. In locating the landfill, which is the most important environmental consideration?  
 (A) the cost of the land (B) the location of the groundwater (C) the proximity to an industrial park (D) the accessibility to a major highway

Ex Output:
B


Ex Input:
Which of these is the most responsible for the changes of the seasons on Earth?  
 (A) Position of the Moon (B) Tilt of Earth on its axis (C) Temperature of the Sun (D) Distance to Mars

Ex Output:

B