在下图点滴板上有四个溶液间反应的小实验，其对应反应的离子方程式书写正确的是

A.a反应：Fe²⁺ +2H⁺ +H₂O₂=Fe³⁺ +2H₂O

B.b反应：HCO₃^-+ OH^-=CO₃^2- +H₂O

C.c反应：H⁺+ OH^-=H₂O

D.d反应：Al³⁺+3NH₃·H₂O=Al(OH)₃↓+3NH₄⁺

— What do you say when your teacher calls your name? 

—            . [ ]

A. I'm here

B. Here it is

C. It's me

D. Thank you