A firm is looking to expand to a larger warehouse.

When considering a new warehouse's environmental impact, the building's total carbon footprint (Option A) should be given the greatest consideration. This encompasses the overall emissions and energy consumption of the warehouse, which has a broader and more significant effect on the environment compared to specific aspects like air conditioning efficiency or light bulb costs. By focusing on the total carbon footprint, the firm can address both direct and indirect emissions, ensuring a comprehensive approach to sustainability. Reference: Environmental Protection Agency guidelines on carbon footprint assessments.