I think it's A but here's an explanation anyway: as you heat the crude oil, the different hydrocarbons, having different boiling points, boil and evaporate up the column. Those with lower boiling points, shorter in chain length, will condense nearer the top of the fractional distillation column. Those that are more viscous, larger in chain size, will have high boiling points, so will evaporate last and condense lower down in the column. Therefore, you achieve all the different oils / materials (oil, petrol, gasoline, tar etc etc). I hope this helps. If not, then a good website to use is 'BBC bitesize, fractional distillation'.
The answer to the question is the total surface area increases and chemical composition changes. Consider the breakdown of rock into smaller pieces, these fragments vary from huge rocks to smaller sizes. As they are so crushed and broken they tend to occupy much of the surface area than when its just a huge rock.
Answer:
A hot spot
Explanation:
In geology, a hot spot is an area of the Earth’s mantle from which hot plumes rise upward, forming volcanoes on the overlying crust.
I hope this helps!