$x, y$ and $z$ are respectively:
$MnO_4^- + x e^- \xrightarrow{\text{Alkaline medium}} MnO_4^{2-}$
$MnO_4^- + y e^- \xrightarrow{\text{Acidic medium}} Mn^{2+}$
$MnO_4^- + z e^- \xrightarrow{\text{Neutral medium}} MnO_2$

• A
  $1, 5, 3$
• B
  $1, 3, 5$
• C
  $5, 3, 1$
• D
  $3, 5, 1$