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.
Aluminium is highly reactive but develops a thin, stable oxide (Al₂O₃) layer on exposure to air, which protects it from further corrosion, making it suitable for cooking utensils.
The textbook explicitly states that aluminium develops a thin oxide layer when exposed to air, making it resistant to further corrosion. This protective layer is the direct reason why a reactive metal like aluminium can still be used safely for everyday purposes like cooking utensils. Both the Assertion and Reason are factually correct, and the Reason directly explains the Assertion — so option (A) is correct. Examiners expect you to identify this cause-effect link clearly.