Final answer:
The given chemical equation C4H₂O4 + O₂ → CO₂ + H₂O represents a combustion reaction. Hence option B is correct.
Step-by-step explanation:
The given chemical equation C4H₂O4 + O₂ → CO₂ + H₂O is a combustion reaction. Thus the correct option is option B.
Combustion reactions occur when a substance reacts with oxygen, producing carbon dioxide and water as the main products.
In this case, the compound C4H₂O4 (oxalic acid) reacts with oxygen (O₂) to form carbon dioxide (CO₂ ) and water (H₂O), which is a characteristic feature of a combustion reaction.