Instructions: 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.
Input: Which of these activities is most likely to have a positive impact on the environment of Earth?  
 (A) Expanding neighborhoods (B) Building factories (C) Constructing highways (D) Creating nature preserves
Output:
D