Data froma recent biodiversity study of the Ukuluku river estuary in Tritonia showed that last year the pollution rate of this environmentally sensitive region was significantly lower than in previous years. The Tritonian government, which spent millions of dollars last year to enforce laws against dumping waste into the river, is claiming that the study data indicate that its increased efforts to halt the pollution are proving effective. Which one of the following, if true, most seriously undermines the government's claim? ['Government agents had to issue fines totaling over $27 million to 650 violators of the river dumping regulations.', 'Much of the money that was designated last year for estuary preservation has been spent on research and not enforcement.', "Factory owner opposition to the government's anti-pollution efforts grew more violent last year in response to the increased enforcement.", 'The largest known polluter on the Ukuluku river relocated to another part of Tritonia, closer to the airport, so as to decrease its shipping costs.']