Which equation best represents the reaction between an acid and a base?

The reaction between an acid and a base is best represented by the equation where an acid (HA) donates a proton (H⁺) to a base (BOH), resulting in the formation of a salt (BA) and water (H2O). In this case, 'HA' signifies the acid, while 'BOH' denotes the base, which typically consists of a metal hydroxide. The products of this neutralization reaction are the salt and water, which is characteristic of acid-base reactions.

This equation encapsulates the essential principles of acid-base chemistry, where the acid and base react to nullify each other's properties, creating a neutral solution. The formation of water and a salt is a hallmark of this type of chemical reaction, emphasizing the exchange of protons that defines acid-base interactions.

The other options listed do not reflect this fundamental interaction: one represents a simple combustion reaction, another depicts a formation of an ionic compound from elements, and yet another represents a different type of reaction that does not involve acid-base interaction. Thus, option A accurately epitomizes the process and outcomes of an acid-base reaction.