Answer: C.) Cu undergoes reduction.
Explanation:
I) Oxidation reaction : involves loss of electrons and there is an increase in oxidation state number.
Fe metal has undergone oxidation, as its oxidation state is changing from 0 to +2 in
.
ii) Reduction reaction : involves gain of electrons and there is a decrease in oxidation state number.
Copper(II) ion has undergone reduction, as its oxidation state is changing from 2+ to 0. Copper ions are getting converted into copper metal.