For $H_3PO_3$ and $H_3PO_4$,the correct choice is:

• A
  $H_3PO_3$ is dibasic and reducing.
• B
  $H_3PO_3$ is dibasic and non-reducing.
• C
  $H_3PO_4$ is tribasic and reducing.
• D
  $H_3PO_3$ is tribasic and non-reducing.