A sustainable competitive advantage for a firm refers to:

an advantage that a firm possesses as a result of being first in a particular market.

an advantage that a firm possesses for a short period of time, till a competitor replicates it.

an advantage that is not easily copied and thus can be maintained over a long period of time.

an advantage companies possess by being already established in a market.

an advantage that a firm has as a result of its ability to produce goods at a lower cost than its competitors.