1. The problem statement, all variables and given/known data 20. Which substance gets reduced in the reaction below? Na2SO4 + 4 C → Na2S + 4 CO a.CO b.Na2SO4 c.C d.Na2S e.this is not an oxidation-reduction reaction 2. Relevant equations none 3. The attempt at a solution i know how to find the oxidation numbers, but why is b the answer I don't understand why. Can anyone explain why? Thanks.