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:
Which is an example of a form of electrical energy?  
 (A) lightning (B) windmill (C) radio waves (D) sound waves

Ex Output:
A


Ex Input:
Which is an example of an organism that has been selectively bred for a particular genetic trait?  
 (A) cats that eat mice (B) cows that graze on grass (C) pigs that form large herds (D) chickens that lay large eggs

Ex Output:
D


Ex Input:
A roller coaster is climbing up the highest hill on its track. At which point will the front car of the coaster most likely have its greatest potential energy?  
 (A) at the bottom of the highest hill (B) at the top of the highest hill (C) at the start of the track (D) at the end of the track

Ex Output:

B