Conservation officers justified their decision to remove a pack of ten coyotes from a small island by claiming that the coyotes, which preyed on wild cats and plover, were decimating the plover population and would soon wipe it out. After the coyotes were removed, however, the plover population plummeted dramatically, and within two years plover could no longer be found on the island. Which one of the following would, if true, most help explain the phenomenon described above? ['The coyotes preyed mainly on wild cats, and wild cats prey on plover.', 'Plover are ground-nesting birds, which makes them easy prey for coyotes.', 'Coyotes are not susceptible to any of the diseases that commonly infect plover or wild cats.', 'The wild cat population on the island was once significantly larger than it is currently.']