Đáp án đúng: B Fe, Na và Mg. $\begin{array}{l}{Fe+CuC}{{{l}}_{{2}}}\xrightarrow{{}}{FeC}{{{l}}_{{2}}}{+Cu}\\{Mg+CuC}{{{l}}_{{2}}}\xrightarrow{{}}{MgC}{{{l}}_{{2}}}{+Cu}\\{Na+}{{{H}}_{{2}}}{O}\xrightarrow{{}}{NaOH+}\frac{{1}}{{2}}{{{H}}_{{2}}}\\{CuC}{{{l}}_{{2}}}{+2NaOH}\xrightarrow{{}}{Cu(OH}{{{)}}_{{2}}}{+2NaCl}\end{array}$