Answer:
Continental Drift Hypothesis.
Step-by-step explanation:
Alfred Lothar Wegener (1880-1930) was a German meteorologist and geophysicist who completed the first hypothesis about Continental Drift. He explained that the continents had onced formed a single mass, a single "continent" and then all began to break apart, until reach their presents positions.
So, according to Wegener's hypothesis, all the land on Earth was part of a single and unique mass, which was separated with the years.
Therefore, Alfred Wegener was best known for the Continental Drift Hypothesis.