Shortly after the Persian Gulf War, investigators reported that the area, which had been subjected to hundreds of smoky oil fires and deliberate oil spills when regular oil production slowed down during the war, displayed less oil contamination than they had witnessed in prewar surveys of the same area. They also reported that the levels of polycyclic aromatic hydrocarbons (PAHs) -- used as a marker of combustion products spewed from oil wells ignited during the war -- were also relatively low, comparable to those recorded in the temperate oil-producing areas of the Baltic Sea. Which one of the following, if true, does most to resolve the apparent discrepancy in the information above? ['Oil contamination and PAH pollution dissipate more rapidly in desert regions than in temperate regions.', 'The Persian Gulf War ended before the oil fires and spills caused as much damage as originally expected.', 'Oil contaminants have greater environmental effects in temperate regions than in desert regions.', 'Peacetime oil production and transport in the Persian Gulf result in high levels of PAHs and massive oil dumping.']