Match the following substances in List-$I$ with their uses in List-$II$:
| List-$I$ (Substance) | List-$II$ (Use) |
| :--- | :--- |
| $(A)$ $Na_2O_2$ | $(I)$ Photoelectric cells |
| $(B)$ $D_2O$ | $(II)$ Antacid |
| $(C)$ $Cs$ | $(III)$ Oxidising agent |
| $(D)$ $Mg(OH)_2$ | $(IV)$ Moderator |

• A
  $A-III, B-IV, C-I, D-II$
• B
  $A-IV, B-III, C-II, D-I$
• C
  $A-III, B-IV, C-II, D-I$
• D
  $A-II, B-IV, C-I, D-III$