Answer:
All the options beside A are correct.
Explanation:
Oxidation reaction is defined as the reaction in which an atom looses its electrons. Here, oxidation state of the atom increases.
[tex]X\rightarrow X^{n+}+ne^-[/tex]
Reduction reaction is defined as the reaction in which an atom gains electrons. Here, the oxidation state of the atom decreases.
[tex]X^{n+}+ne^-\rightarrow X[/tex]
So, when metal gets oxidized by the other substance , there is direct contact of metal and oxidizer.
During corrosion of metal ,there is a loss of electrons from the metal atom which increases its oxidation state and other oxidizer itself get reduced.