AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
(A) Both A and R are true, and R is the correct explanation of A.
Carbon cannot reduce Na₂O or Al₂O₃ because sodium and aluminium are more reactive than carbon and have greater affinity for oxygen, so carbon cannot displace them from their oxides.
The reactivity series places Na and Al above carbon. A more reactive metal has greater affinity for oxygen and cannot be displaced by a less reactive reducing agent like carbon. Thus R directly and correctly explains A — making option (A) the right choice. Remember: carbon can reduce oxides of metals below it in the reactivity series (e.g., ZnO, PbO), but not Na₂O or Al₂O₃.