The correct answer is option A, Paleomagnetism
Paleomagnetic studies gave way to the modern tectonic plate theory. The movement of plates was established through these studies. Before these studies , the continental drift theory was the only theory which explained the drifting of continents. Paleomagnetic studies showed that either the north pole or the plates are moving. Under these studies it was established that North pole wanders all around the globe. Also the magnetic poles of earth get reversed for a period of time and due to these reversals the lithosphere had to be in motion in order to maintain normal and reversed polarity crust
