You will be given a definition of a task first, then some input of the task.
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.

The growing human population has many practices that adversely impact the environment. Acid rain is one example of environmental damage that is related to human activities. Which human activity is most likely the largest contributor to acid rain?
(A) burning fossil fuels in power plants (B) using pesticides on agricultural crops (C) dumping waste matter into ocean waters (D) clearing native forests for industrialization
Output:
A