You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
You are given a science question (hard-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.

Which event can cause a large rock to become soil over time? 
 (A) decaying (B) an earthquake (C) a landslide (D) weathering
Solution: D
Why? Under the action of heat, cold, rain, wind, and other atmospheric factors, the rock breaks down physically into small fragments that become the parent material of the soil. Also, atmospheric factors change according to weather.

New input: Which of the following is LEAST responsible for the weathering of rocks?  
 (A) freezing (B) plant growth (C) rain (D) lightning
Solution:
D