Which of the following strategies can be employed to reduce potable water use for landscaping...

Smart irrigation controllers are the best answer because they adjust irrigation schedules based on weather, soil moisture, evapotranspiration, rainfall, and other site conditions. In LEED Water Efficiency, outdoor water reduction begins with efficient landscape design and efficient irrigation. Graywater, rainwater, and native plants can also reduce potable water use, but the wording specifically asks for a strategy based on irrigation schedules with weather conditions. That directly describes weather-based smart irrigation controls. Option A provides alternative water sources, not schedule-based control. Option B reduces irrigation demand through plant selection, but it does not actively adjust watering schedules. Option D is incorrect because turfgrass typically increases irrigation demand and can make outdoor water reduction harder to achieve.