The giant Chicxulub crater in Mexico provides indisputable evidence that a huge asteroid, about six miles across, struck Earth around the time many of the last dinosaur species were becoming extinct. But this catastrophe was probably not responsible for most of these extinctions. Any major asteroid strike kills many organisms in or near the region of the impact, but there is little evidence that such a strike could have a worldwide effect. Indeed, some craters even larger than the Chicxulub crater were made during times in Earth' s history when there were no known extinctions. Which one of the following, if true, would most weaken the argument? ['There is no evidence that any other asteroid of equal size struck Earth at the same time as the asteroid that produced the Chicxulub crater.', "During the period immediately before the asteroid that produced the Chicxulub crater struck, most of the world's dinosaurs lived in or near the region of the asteroid's impending impact.", 'Fossils have been discovered of a number of dinosaurs that clearly died as a result of the asteroid impact that produced the Chicxulub crater.', 'The size of a crater caused by an asteroid striking Earth generally depends on both the size of that asteroid and the force of its impact.']