ZnO is best reduced by C and not by CO?

Question

ZnO is best reduced by C and not by CO?

Answer 1

CO gas acts as abetter reducing agent at lower temperature i.e.below 673K and  C above this temperature. Since, activation energy for the reduction of ZnO is acquired at higher temprtature and so ZnO is reduced at about1723K and at this temprtature COKE is the better reducing agent than CO gas.  

Answer 2

carbon in its elemental form reacts wid Oxygen 2 form CO which then gives us Zn. this reaction is faster and gives a more pure form of zinc than what is obtained in the latter reaction.