What is the increasing order of stability of the $+2$ oxidation state for the given group $14$ elements?

• A
  $Ca^{2+} < Ba^{2+} < Sr^{2+}$
• B
  $Pb^{2+} < Ge^{2+} < Sn^{2+}$
• C
  $Ge^{2+} < Sn^{2+} < Pb^{2+}$
• D
  $Cu^{2+} < Au^{2+} < Ag^{2+}$