Embodied energy in materials is one of the three core pillars of the EDGE standard, focusing on reducing the environmental impact of construction materials. The EDGE User Guide lists measures that specifically target embodied energy: "To reduce embodied energy in materials, EDGE includes measures such as the use of fly ash concrete, which substitutes a portion of cement with fly ash, a byproduct of coal combustion, thereby lowering the embodied energy and carbon footprint of concrete production" (EDGE User Guide, Section 7.2: Materials Efficiency Measures). Option B, fly ash concrete, directly aligns with this measure, as it reduces the need for high-energy cement production. Option A (external shading) impacts energy by reducing cooling loads but does not directly address embodied energy: "External shading reduces operational energy use but does not contribute to embodied energy savings unless the shading materials themselves are low-impact, which is not specified in EDGE” (EDGE User Guide, Section 3.5: Passive Design Strategies). Option C (occupancy sensors) is an energy efficiency measure for lighting, not materials: "Occupancy sensors reduce lighting energy use but have no direct impact on embodied energy in materials" (EDGE User Guide, Section 4.4: Lighting Efficiency Measures). Option D (low-flow shower heads) targets water efficiency, not materials: "Low-flow shower heads reduce water consumption, but their embodied energy impact is minimal and not a focus of EDGE materials measures" (EDGE User Guide, Section 5.2: Water Efficiency Measures). The EDGE MethodologyReport further elaborates: "Fly ash concrete can reduce embodied energy by up to 20% compared to traditional concrete, making it a key measure in EDGE for materials efficiency, especially in high-volume applications like hospitals or hotels" (EDGE Methodology Report Version 2.0, Section 6.1: Embodied Energy in Materials). Other materials measures in EDGE, such as using recycled steel or bamboo, are not listed among the options, making fly ash concrete (Option B) the correct choice for reducing embodied energy.