You have four metals $A,B,C$ and $D$ in $1\mathrm{.}00M$ solutions of $A^{2+},B^{2+},C^{2+}$ and $D^{2+}$ respectively. The following results are found when some of the half$-$cells are connected together.

$\backslash$table$[[$Cathode$,$Anode,Cell voltage$],[$C$,$A$,0\mathrm{.}75V$