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.
--------
Question: What form of energy is being used when a person pushes a wooden block across the floor?  
 (A) mechanical (B) magnetic (C) sound (D) electrical

Answer: A


Question: Which scientist is known for his genetics experiments with pea plants?  
 (A) Charles Darwin (B) Gregor Mendel (C) Carolus Linnaeus (D) Robert Hooke

Answer: B


Question: Moving water in a river is considered a renewable resource because it  
 (A) carries dissolved oxygen (B) easily erodes sediments (C) is made of natural gas (D) can be recycled by nature over time

Answer:
D