下列反应中，水作氧化剂的是                                     (　　)

A．2Na₂O₂＋2H₂O===4NaOH＋O₂↑

B．C＋H₂OCO＋H₂

C．Cl₂＋H₂O===HCl＋HClO

D．2F₂＋2H₂O===4HF＋O₂

Li Hua’s shoes are as _______ as Zhang Hui’s.

A．cheap

B．cheaper

C．the cheaper

D．The cheapest