$Cr^{2+}$ and $Mn^{3+}$ both possess $d^4$ electronic configuration. Therefore,

• A
  $Mn^{3+}$ is an oxidizing agent while $Cr^{2+}$ is a reducing agent
• B
  Both are reducing agents
• C
  $Mn^{3+}$ is a reducing agent while $Cr^{2+}$ is an oxidizing agent
• D
  Both are oxidizing agents