Which of the following best describes continents?

The correct choice reflects the definition of continents as large, significant landmasses that include various global regions. Continents are the primary divisions of land on Earth, and they typically encompass distinct geographic, cultural, and ecological characteristics. They are considerably larger than smaller landmasses or islands, and each continent contains multiple countries, climates, and ecosystems that contribute to its unique identity.

The focus on "major global regions" is especially pertinent, as continents serve as the backbone for geopolitical boundaries and cultural exchange worldwide. Understanding continents in this way is fundamental for grasping not just geography but also the interconnectedness of global societies, economies, and environmental issues. The other choices describe either smaller landforms or entirely different geological features, thus not satisfying the criteria for what constitutes a continent.