In LCA, what do system boundaries determine?

• A. The color of the product
• B. The market price
• C. The consumer preferences
• D. The physical limits of the product's life cycle

Answer: (D)

System boundaries in life cycle assessment define what is inside the analysis and what is outside. They set the scope by deciding which stages and processes are included (for example, material extraction, manufacturing, distribution, use, and end-of-life) or excluded, effectively outlining the physical limits of the product’s life cycle being studied. This is why the boundaries determine the scope of the assessment—from cradle to grave, cradle to gate, or other boundaries—and shape what emissions, resource use, and impacts are counted. Colors, market price, and consumer preferences aren’t dictated by these boundaries; they’re external factors not defined by the life cycle scope.