What was the name of the supercontinent that included all present-day continents?

The answer is Pangaea because it refers to the supercontinent that existed during the late Paleozoic and early Mesozoic eras, approximately 335 to 175 million years ago. Pangaea combined all of the Earth's landmasses into a single, vast continent and is significant in the study of plate tectonics and the geological history of the planet. The concept of Pangaea helps explain the distribution of fossils and the similarity of rock formations found across continents that are now widely separated by oceans.

Gondwana is a separate ancient supercontinent that existed before Pangaea and included landmasses that are now parts of Africa, South America, Australia, Antarctica, and the Indian subcontinent. Laurasia was the northern segment of Pangaea after it began to break apart, comprising what would become North America, Europe, and Asia. Atlantis is often referred to in mythology and does not represent a scientifically recognized landmass in geological history. Therefore, Pangaea is the correct answer as it directly pertains to the supercontinent encompassing all present-day continents.