Some paleontologists have suggested that Apatosaurus, a huge dinosaur, was able to gallop. This, however, is unlikely, because galloping would probably have broken Apatosaurus' s legs. Experiments with modern bones show how much strain they can withstand before breaking. By taking into account the diameter and density of Apatosaurus leg bones, it is possible to calculate that those bones could not have withstood the strains of galloping. Which one of the following most accurately expresses the conclusion drawn by the argument as a whole? ['Galloping would probably have broken the legs of Apatosaurus.', 'It is possible to calculate that Apatosaurus leg bones could not have withstood the strain of galloping.', 'If galloping would have broken the legs of Apatosaurus, then Apatosaurus was probably unable to gallop.', 'The claim of paleontologists that Apatosaurus was able to gallop is likely to be incorrect.']