What is the primary role of a reducing agent in a redox reaction?

The primary role of a reducing agent in a redox reaction is to be the species that donates electrons to another substance, thereby facilitating its reduction. When the reducing agent donates electrons, it undergoes oxidation itself, meaning it loses electrons. This dual nature of electron transfer — where one species experiences a decrease in oxidation state while the other experiences an increase — is central to the concept of redox reactions.

In this context, the correct answer emphasizes the action of losing electrons, which defines the reducing agent's role in the reaction. Through its electron donation, the reducing agent enables the reduction of another chemical species, reflecting the intricate balance of oxidation and reduction processes in chemical reactions.

While it is true that some reducing agents can be metals, it is not limited to this group, as nonmetals can also serve as reducing agents under certain circumstances. Additionally, the classification of a reducing agent does not depend on its being a non-metal that gains electrons; rather, its defining feature is its capacity to lose electrons and therefore reduce another substance.