In which of the following compound the highest valency of copper is equal to the lower valency of other metals?

In $FeC{l}_2$  valency of Fe is 2, and it's the lower valency

In $SnC{l}_2$  valency of Sn is 2, and it's the lower valency.

$CuC{l}_2$  valency of Cu is 2, and it's the higher valency.

So higher valency of copper is equal to the lower valency of Fe and Sn.