In 1915 the German geologist and meteorologist Alfred Wegener first proposed the theory of continental drift, which states that parts of the Earth's crust slowly drift atop a liquid core. The fossil record supports and gives credibility to the theories of continental drift and plate tectonics.

Why was the continental drift theory rejected at the time of its proposal?
A) It did not explain the mechanism causing the movement of continents.
B) It did not explain the mechanism behind the discovery of continents.
C) It did not explain the mechanism behind the existence of continents.
D) It did not explain the mechanism causing the formation of continents.