Which term best describes something that is engagingly stimulating or provocative?

The term that best describes something that is engagingly stimulating or provocative is "piquant." This word originates from French and is often used to describe something that has a sharp, stimulating quality, whether in flavor or in a broader sense, such as ideas or discussions that are intriguing and thought-provoking. When applied to concepts, conversations, or artistic works, "piquant" implies an ability to arouse interest and provoke thought, making it a fitting choice for the description of something that captivates attention in a lively manner.

The other options do not convey this idea effectively. "Perfunctory" refers to something done merely as a routine duty, lacking interest or enthusiasm. "Pethora" is not a known word in this context and may confuse readers. "Perpetual" denotes something that is endless or continuous, without relating to the aspect of engagement or stimulation. Thus, "piquant" is the only term that embodies the notion of being stimulating or provocative.