What characteristic best defines "protracted"?

The term "protracted" is best defined as "long-lasting." It is derived from the Latin root that means to extend or prolong. When something is described as protracted, it indicates that it has been extended in time, duration, or effort, leading to a situation or condition that persists longer than expected.

In the context of this question, the other options do not convey this same sense of continuity or duration. While "ample" suggests abundance or adequacy, and "unhurried" refers to a lack of rush or speed, they do not capture the essence of something that is enduring over a long period. "Discontinued" implies that something has come to an end, which directly contrasts with the idea of being long-lasting. Therefore, choosing "long-lasting" accurately reflects the fundamental meaning of the word "protracted."