During the recent spate of brushfires in the Southwest, homeowners who lived near affected areas were advised to douse their roofs with water to prevent their houses from catching fire before evacuating the area. After the fires were brought under control and the homeowners were allowed to return to the area, many who doused their roofs discovered significant fire damage to their houses. Clearly, then, dousing their roofs was a wasted effort. Which of the following, if true, would most weaken the conclusion above? ['Not all homeowners who doused their roofs did so to the same extent.', 'The houses that suffered the least damage were those in which the owners remained and continuously doused the roofs.', 'The houses of owners who did not douse the roofs with water suffered appreciably more fire damage than did those of owners who did douse the roofs with water.', 'The fire insurance rates for those who doused their roofs did not increase after the fire.']