Final answer:
Alfred Wegener developed the hypothesis of continental drift based on the existence of matching fossils and mountain ranges on different continents.
Step-by-step explanation:
Alfred Wegener developed the hypothesis of continental drift based on several observations. One key observation was the existence of matching fossils on separate continents.
For example, fossils of the same species were found in South America and Africa, indicating that these continents were once connected. Wegener also noted the presence of matching mountain ranges on different continents, further supporting the idea of continental drift.