Researcher: Dinosaur fossils come in various forms, including mineralized bones and tracks in dried mud flats. However, mineralized dinosaur bones and dinosaur tracks in dried mud flats are rarely found together. This isn' t surprising, because creatures that scavenged dinosaur carcasses most likely frequented mud flats to find food. Which one of the following, if true, would most strengthen the researcher's argument? ['Dinosaur fossils other than mineralized bone or tracks in dried mud flats are quite common.', 'Scavengers commonly drag a carcass away from the site where it was found.', 'Dinosaur tracks are also found in locations other than mud flats.', 'Researchers have found more fossil dinosaur tracks than fossil dinosaur bones.']