The correct options are
A Cl2+2e−→2Cl−
D Fe3++e−→Fe2+
Reduction :
It is a process in which an atom or a group of atoms taking part in a chemical reaction gains one or more electrons.
For example:
i. Cl2+2e−→2Cl−
ii. Fe3++e−→Fe2+
Therefore, in both the examples metioned above, there is gain of electrons. So, they are undergoing reduction .