What does "quintessence" signify?

The term "quintessence" refers to the purest or most concentrated essence of something. Historically, it was used in medieval philosophy to describe the fifth element, beyond the four classical elements of earth, water, air, and fire, which made up the heavenly bodies and was thought to be the essence of all matter. In contemporary usage, it embodies the idea of an ideal example or the most typical manifestation of a quality or concept.

This is why "the purest essence or form of something" is the most accurate choice. It captures the notion of quintessence as being the distilled representation of a characteristic or quality, devoid of any impurities. The other options lack this specificity or connection to the term's historical and philosophical roots, making them less suitable in relation to the definition of quintessence.