Which of the following is an example of an isthmus?

An isthmus is a narrow strip of land that connects two larger land masses and is typically bordered by water on both sides. Central America serves as a prime example of this geographic feature, as it links North America to South America. The Panama Canal, which runs through Central America, further illustrates the significance of this region as it allows maritime traffic to move between the Atlantic and Pacific Oceans, emphasizing the isthmus's role in connecting different parts of the globe.

The other options do not represent isthmuses. The Aleutian Islands are an archipelago, meaning they consist of multiple islands rather than a connecting strip of land. Northern Greenland is primarily a landmass surrounded by water but lacks the characteristic narrowness of an isthmus that connects two larger land areas. Florida, while a peninsula, does not connect two larger landmasses in the way that an isthmus does, as it is surrounded by water on three sides rather than linking two continents. Thus, Central America's status as an isthmus aligns perfectly with the definition, making it the correct answer.