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 two most common minerals located in Earth's crust are B) Feldspar and quartz
(Earth Science- Geology, the Environment, and the Universe book)
Population means the number of people in a geographic area. It can also be used for subgroups of people or animals.
Those geographic helped to protect the Roman Empire.
