TASK DEFINITION: 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.
PROBLEM: Which of the following is the best example of potential energy?  
 (A) a fallen rock (B) a burning match (C) a liter of gasoline (D) a red-hot piece of iron

SOLUTION: C

PROBLEM: A pot is heated on a stove. Which process causes the metal handle of the pot to also become hot?  
 (A) combustion (B) convection (C) radiation (D) conduction

SOLUTION: D

PROBLEM: Which health condition is an infectious disease?  
 (A) pneumonia caused by microorganisms (B) heart problem caused by a high-fat diet (C) lung cancer caused by smoking (D) eye damage caused by ultraviolet light

SOLUTION:
A