The correct answer is - Magma generated from a hot spot burned through the overlying plate to create volcanoes.
The Hawaiian Islands are all formed as a result of volcanic activity of a hot spot. The hot spot is stationary, but the islands are in the shape of a chain, not all in the same place. Also, the rocks on the islands that do not have active volcanoes are older, than the ones that do have volcanic activity. This suggests that the Pacific plate is moving. According the direction in which the islands are arranged, the Pacific plate seems to move toward northwest. As it moves, it moves over the hot spot. Since the hot spot is stationary, as the Pacific plate moves, eventually the volcanic activity will stop on the island that has moved further away from the hot spot. The magma from the hot spot will penetrate through the crust that came to be over it. That will result in new volcanic island emerging from the sea over the hot spot. The process goes on for millions of years, and it can result in hundreds of islands of volcanic origin.
B & C in my opinion. If it asks for one— B. is what I would choose.
Medicine and safety regulations at the work place.
Arenal Volcano is in the middle of the continent
The Congo and Niger rivers have interesting irregular courses, and instead of going just in a certain direction, they circle around big areas. This is due to the shape of the landscape, and also because of the types of rocks in the surrounding areas where these two rivers flow.
The shape of the landscape is crucial in the course of a river, since every river is moving through the lowest parts where there isn't obstacles, so these rivers have followed that pattern and it turned out to give them irregular course. Also, the types of rocks on their way are very important, so these rivers managed to get through the sediment rocks as they are easy to erode, but haven't been able to break through the igneous rocks that are much harder.
