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: Which of the following properties best describes a material's ability to resist scratching?  
 (A) weight (B) flexibility (C) length (D) hardness

Output: D


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

Output: A


Input: Consider Input: What event happens in a daily cycle?  
 (A) cliffs erode (B) rivers flood (C) volcanoes erupt (D) high and low tides


Output: D