Oxidation means that atom or ion loses electrons.
Reduction means that atom or ion takes electrons.
Cu²⁺ +2e⁻ ---> Cu⁰ , We can see that ion Cu²⁺ takes electrons, so this is reduction.
Fe⁰ ------> Fe⁺³ + 3e⁻, We can see that atom Fe lost electrons, so this is oxidation.
Reduction:
A., C., E.
Oxidation:
B., D.
