The first two sentences of the second paragraph (lines 22-29) state:
"To model oil field flow using a computer requires the simulation of the distribution of the oil at tens of thousands of locations throughout the field. At each location, hundreds of simultaneous calculations must be made at regular time intervals relating to such variables as temperature, direction of oil flow, viscosity, and pressure, as well as geologic properties of the basin holding the oil."
These sentences discuss the complexities of modelling oil field flow. As such, we can definitively eliminate answer choices A, C, and E.
Reading back a bit, the final sentences of the first paragraph (lines 14-21) state:
"...one of the most computationally difficult problems: predicting the flow of oil through the subterranean geologic formations that make up oil fields. Until that time, supercomputers had been used for oil field calculations, but because these supercomputers worked sequentially, they were too slow and inefficient to accurately predict such extremely complex movements."
Therefore, the first two sentences of the second paragraph illustrate why modelling oil fields is so complex, supporting the conclusion of the first paragraph that supercomputers were too slow and inefficient to accurately predicts the movements of oil.
The first two sentences of the second paragraph do not discuss a specific mathematical model used to understand the system, so we can eliminate answer choice D.
This leaves us with answer choice B which states that the function of the first two sentences of the second paragraph is to help explain why supercomputers are unable to accurately predict the movements of oil through underground geologic formations. This supports our conclusion drawn about these sentences above and, therefore, is the correct answer.
Hope this was helpful! Let us know if you have any further questions.
