Which of the following strategies focuses on reducing greenhouse gas emissions through clean energy sourcing?

Zero-emissions power sourcing is the best answer because it directly reduces greenhouse gas emissions associated with building energy use. LEED Energy and Atmosphere emphasizes reducing energy demand, improving energy efficiency, using renewable energy, and supporting cleaner grid-source power. Purchasing or generating power from renewable or zero-emissions sources reduces reliance on fossil-fuel-based electricity. Low-emitting materials are important for Indoor Environmental Quality because they reduce VOCs and other indoor pollutants, but they do not directly reduce energy-related greenhouse gases. Urban heat island reduction is a Sustainable Sites strategy that can indirectly lower cooling demand but is not primarily a clean energy sourcing strategy. Potable water metering supports Water Efficiency tracking, not greenhouse gas reduction through energy supply.