According to the theory proposed by Harry Hess, what causes continents to move?
The correct answer is : seafloor spreading.
Earlier, in 1912 Alfred Wegener produced evidence that the continents are in motion but this idea was shelved as he could not explain what forces the continents to move. So, almost 50 years later Harry Hess confirmed Wegener's ideas by using the evidence of seafloor spreading to explain what moved continents.
