When chemical x is reduced, which of these expressions would be an accurate representation of its reduced state?

Is this what you wanted if not I can provide with more info:                                       reduction is the part of an Oxidation–Reduction reaction in which there is a gain of electrons by a species or a decrease of the oxidation number of an atom. So C, there is no change so NOT a reduced state. In A the oxidation number has to go up by 2 for oxygen's oxidation number is always -2, so the leaves B, were the bond with the hydrogen atom would donate an electron, thus reducing X

Copper, silver, aluminum, cobalt, chromium, mercury 

Ithink is a because if say increased in electronegativity