Answer:
Option A. are mostly non-metals.
Explanation:
Oxidising agents are mostly non-metals because non metals gains electron from the metal during chemical bond and we know that oxidising agent is electron accepter not donar. For example, Sodium is a metal react with chlorine which is a non-metal so the sodium losses electron and this electron is gain by chlorine atom forming sodium chloride. In this example chlorine is a non-metal which gains electron.
