$MnO_{2} + HCl \xrightarrow{\Delta} A_{(g)}$
$A_{(g)} + F_{2} (\text{excess}) \rightarrow B_{(g)}$
$B_{(l)} + U_{(s)} \rightarrow C_{(g)} + D_{(g)}$
The gases $A$,$B$,$C$ and $D$ are respectively

• A
  $Cl_{2}, ClF_{3}, UF_{6}, ClF$
• B
  $O_{2}, O_{2}F_{2}, U_{2}O_{3}, OF_{2}$
• C
  $Cl_{2}, ClF, UF_{6}, ClF_{3}$
• D
  $O_{2}, OF_{2}, U_{2}O_{3}, O_{2}F_{2}$