The correct answer is - C. hot spots in the mantle.
The Hawaiian Islands are a volcanic islands. They are lying above a hot spot. The hot spot volcanoes, unlike the other ones, are far away from the boundaries of the tectonic plates and they are emerging on places were there's hot spots. These hot spots manage to penetrate through the crust and get the magma from the mantle up to the surface and create volcanic islands in meantime.
pov: you are cheating in iip exam
~Hello there!
Your question: Which oceans have the greatest number of rivers flowing into them?
Your answer: Atlantic and the Indian ocean have the greatest number of rivers flowing into them.
Hope this helps! :3