Detailed Instructions: 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.
Q: Raising livestock, such as sheep and cattle, results in the production of large amounts of methane gas (CH4). Methane has the same effect in the atmosphere as carbon dioxide (CO2). As more livestock are raised to provide food for humans, what is the most likely effect of the increase in methane?
(A) acid rain (B) ozone thinning (C) water pollution (D) global warming
A:
D