The correct answer is:
a. The theory had sufficient evidence that the continents were aligned, but could not explain HOW the continents moved.
Alfred Wegener's Continental Drift Theory was initially rejected primarily because, while he presented compelling evidence showing the fit of continental shapes and similarities in fossils and geological features across continents, he could not provide a convincing mechanism for how the continents moved. At the time, the prevailing thought regarding the stability of continents and the nature of Earth's lithosphere made it difficult for many geologists to accept his ideas.