A recent poll showed that almost half of the city' s residents believe that Mayor Walker is guilty of ethics violations. Surprisingly, however, 52 percent of those surveyed judged Walker' s performance as mayor to be good or excellent, which is no lower than it was before anyone accused him of ethics violations. Which one of the following, if true, most helps to explain the surprising fact stated above? ['About a fifth of those polled did not know that Walker had been accused of ethics violations.', 'Walker has defended himself against the accusations by arguing that the alleged ethics violations were the result of honest mistakes by his staff members.', "In the time since Walker was accused of ethics violations, there has been an increase in the percentage of city residents who judge the performance of Walker's political opponents to be good or excellent.", 'Almost all of the people who believe that Walker is guilty of ethics violations had thought, even before he was accused of those violations, that his performance as mayor was poor.']