Hypothesis that states that the continents were once one large mass that broke apart?

Continental drift

Explanation:

Alfred Wagener told about continental drift. He said that continents were a single land mass called Pangaea. They were separated and relocated in the form of different continents. The drifting happens due to the movement of tectonic plates above the magma. As a result, the land mass was broken down into different landforms.  These broken parts were carried slowly and form the continents. The continents are now also moving slowly