Life-cycle assessment yields emissions per unit of energy or distance.

• A. True, and it includes emissions from extraction through end-of-life.
• B. False; it only measures combustion emissions.
• C. False; it measures only energy input.
• D. False; it excludes use phase.

Answer: (A)

Life-cycle assessment looks at all greenhouse gas emissions tied to a product or service across its whole life, and then expresses that total per unit of energy produced or per unit distance traveled. That means accounting for every stage from resource extraction and material processing to manufacturing, transportation, use, maintenance, and end-of-life disposal or recycling. Because of this cradle-to-grave approach, the emissions include the energy and emissions embedded in obtaining materials, building the system, and eventually decommissioning it, not just what happens during use or combustion.

So the statement is true: the metric is emissions per unit of energy or distance, and the analysis covers extraction through end-of-life. The other ideas—that LCAs measure only combustion emissions, or only energy input, or exclude use phase—don’t fit because a comprehensive LCA includes multiple life-cycle stages and uses the chosen functional unit (like per kWh or per passenger-km) to express the overall emissions.