Municipal officials originally estimated that it would be six months before municipal road crews could complete repaving a stretch of road. The officials presumed that private contractors could not finish any sooner. However, when the job was assigned to a private contractor, it was completed in just 28 days. Which one of the following, if true, does most to resolve the discrepancy between the time estimated for completion of the repaving job, and the actual time taken by the private contractor? ['The labor union contract for road crews employed by both municipal agencies and private contractors stipulates that employees can work only eight hours a day, five days a week, before being paid overtime.', 'Many road-crew workers for private contractors have previously worked for municipal road crews, and vice versa.', 'Municipal agencies must conduct a lengthy bidding process to procure supplies after repaving work is ordered and before they can actually start work, whereas private contractors can obtain supplies readily as needed.', 'Road repaving work can only be done in the summer months of June, July, and August.']