Bunuel wrote:
A recent examination of the waters of the Southern Ocean showed a substantial increase in pollution levels, which is usually caused by routine oil spills during industrial drilling operations in the area. Last month, an article published in the biannual newsletter of a prominent environmental organization attributed this increase to the operations of Gaston Inc., an oil company with several large deep-water drilling operations. This claim is not undermined by the finding that none of Gaston Inc.’s oil plants in the Southern Ocean had any oil spills, because ____________.
A. most increases in the pollution levels of oceans take place because of deep-water drilling operations
B. oil usually floats several feet below the surface of the ocean rather than at the surface itself
C. pollutants that enter the ocean sometimes take decades to affect the marine environment
D. tankers that transport oil from drilling plants to offshore locations often develop leaks
E. calculated amounts of oil are sometimes deliberately discarded by oil plants to maintain water pressure in the area surrounding the plant
The premise says that "none of Gaston Inc.’s oil plants in the Southern Ocean had any oil spills" which means oil did not spill due to deep-water drilling by Gatson Inc. Option (A) is out.
Option (B) is irrelevant because the oil that has spilled is what our concern is, not where it is floating.
Option (C) is also irrelevant.
Option (D), well, is a possible way that leads to pollution.
Option (E) is again irrelevant.
Option (D) is correct.