Which of the Following Does Not Involve CO Acting as a Reducing

Multiple Choice

Which of the following does not involve CO acting as a reducing agent?

A) PbO(s) + CO(g) $\rarr$ Pb(s) + CO₂(g) .
B) CO(g) + H₂O(g) $\rarr$ CO₂(g) + H₂(g) .
C) 2CO(g) + O₂(g) $\rarr$ 2CO₂(g) .
D) Ni(s) + 4CO(g) $\rarr$ Ni(CO) ₄(g) .
E) Fe₂O₃(s) + 3CO(g) $\rarr$ 2Fe(s) + 3CO₂(g) .