A government regulation that requires all new buildings to meet a minimum energy‑efficiency standard will most likely:

The correct option is Reduce the amount of energy used by buildings over their lifetime. This answer is correct because it matches the approved learning objective to describe how government actions such as taxation, regulation or emissions targets may reduce carbon footprints in the subtopic The carbon footprint and its reduction.

The correct option is Reduce the amount of energy used by buildings over their lifetime. Reduce the amount of energy used by buildings over their lifetime is correct because it directly supports the approved learning objective to describe how government actions such as taxation, regulation or emissions targets may reduce carbon footprints. This belongs to the subtopic The carbon footprint and its reduction within Carbon dioxide and methane as greenhouse gases, so the explanation must stay tied to that curriculum context. The other options are incorrect because they either do not answer this learning objective, use a vague statement, or move away from The carbon footprint and its reduction.