To reduce the mosquito population in a resort area, hundreds of trees were planted that bear fruit attractive to birds. Over the years, as the trees matured, they attracted a variety of bird species and greatly increased the summer bird population in the area. As expected, the birds ate many mosquitoes. However, the planting of the fruit trees had the very opposite of its intended effect. Which one of the following, if true, most helps to explain the apparently paradoxical result? ['Most of the species of birds that were attracted by the trees that were planted did not eat mosquitoes.', 'Increases and decreases in mosquito populations tend to follow a cyclical pattern.', 'The species of birds that were attracted in the greatest number by the fruit of the trees that were planted did not eat mosquitoes.', 'The birds attracted to the area by the trees ate many more insects that prey on mosquitoes than they did mosquitoes.']