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:
Some types of bacteria can only live where oxygen is not present. These bacteria were well adapted to life on Earth over 2 billion years ago. Which of the following changes caused many of these bacteria to become extinct?  
 (A) the slow movement of tectonic plates (B) the varying temperatures of each season (C) an increase in volcanic activity under the oceans (D) an increase in the number of photosynthetic organisms

Ex Output:
D


Ex Input:
In an electric motor, electrical energy is converted into  
 (A) mechanical energy. (B) chemical energy. (C) thermal energy. (D) light energy.

Ex Output:
A


Ex Input:
Which relationship between Earth's outer core and inner core generates a large portion of Earth's magnetic field?   
 (A) their relative masses (B) their relative motions (C) their relative diameters (D) their relative circumferences

Ex Output:

B