题目内容：

下表所列各组物质中，物质之间通过一步反应就能实现如图所示转化的是

 

 

                 a                          b                         c

A              Al                         AlCl₃                   Al(OH)₃

B               HNO₃                   NO                     NO₂

C               S                          SO₃                     H₂SO₄

D              Si                         SiO₂                    H₂SiO₃