How can improving energy efficiency in homes help reduce carbon footprints?

The correct option is By reducing the amount of energy needed for heating and cooling. This answer is correct because it matches the approved learning objective to describe how individual actions such as reducing energy use, transport choices and recycling may reduce carbon footprints in the subtopic The carbon footprint and its reduction.

The correct option is By reducing the amount of energy needed for heating and cooling. By reducing the amount of energy needed for heating and cooling is correct because it directly supports the approved learning objective to describe how individual actions such as reducing energy use, transport choices and recycling 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.