who knows... said:
for it to be a reducing agent it has to undergo oxidation and thus lose electrons...
I think its because in d, the chlorine is bonded from all four places (draw a lewis dot diagram) and can't give up any more of its electrons where as in the others it can give up electrons...this is because not all of the electrons in the a,b,c chlorines are shared with oxygens and thus it can lose some
please someone correct me if I'm wrong...