Q: 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.
As the human population grows, the demand for natural resources increases. Which activity wastes a natural resource?  
 (A) turning off lights (B) using public transportation (C) throwing away aluminum cans (D) opening windows to cool a house
A:
C