Final answer:
The Uniformitarian theory posits that slow geological processes have shaped the Earth over long periods, which aligns with option B of the student's question.
Step-by-step explanation:
According to Uniformitarian theory, the correct statement is B. Slow processes are responsible for shaping the Earth. This concept, proposed by Scottish geologist Charles Lyell, suggests that Earth's geologic features are the result of slow and consistent geological processes such as erosion, sedimentation, and plate tectonics.
The idea of Uniformitarianism asserts that the same natural laws and processes that operate in our present-day geological system have always operated in the past at roughly the same rates, leading to the continuous formation of the Earth's surface over time. This is in contrast to catastrophism, which attributes Earth's features to rapid, short-lived, violent events like floods and volcanic eruptions.
Plate tectonics, as a related geological theory, explains how the movement of Earth's plates over geological timescales has led to the drifting of continents, the creation of mountains, and the occurrence of earthquakes along fault lines. German scientist Alfred Wegener built upon this theory with his idea of continental drift, proposing a supercontinent called Pangea that existed around 200 million years ago.