IMAT 2012 Q67 [Chemical Reactions]

Consider the following reactions.

{C_2H_5Br + OH­^- → C_2H_5OH + Br^-}

{Ba^{2+}(aq) + SO4^{2-}→ BaSO_4(s)}

{Mg(s) + Cu^{2+}(aq) → Mg^{2+}(aq) + Cu(s)}

Which one of the following types of reaction is NOT included in this list?

A. substitution
B. oxidation/reduction
C. displacement
D. precipitation
E. elimination