If you are talking about Alfred Wegener, then his Hypothesis was Continental Drift, a Theory that suggested that all the continents were once one large supercontinent, named Pangaea, But drifted apart from each other over a long period of time.
The correct answer is a dichotomous key. Basically, you use the key to decide what species an organism is by looking at what traits it has, and if it doesn't have some traits you can instantly rule out a large number of species which brings you closer to your answer of what the species is that you're looking at.
