Gselect the correct statements. i. reduction is the loss of electrons, and oxidation is the gain of electrons ii. reduction is the gain of electrons, and oxidation is the loss of electrons iii. the reactant that is reduced is also called the reducing agent, and the reactant that is oxidized is called the oxidizing agent. iv. the reactant that is oxidized is also called the reducing agent, and the reactant that is reduced is called the oxidizing agent. v. the sum of all the oxidation numbers in a compound is equal to the charge of that compound.