Which of the following statements, if true, most seriously weakens the argument? A. A microfiber synthetic shirt costs one-half the price of a natural-fiber shirt to maintain. B. The production of microfiber synthetic clothes necessitates garment factories to renovate obsolete machinery and to hire extra workers to operate the new machines. C. The upkeep of natural-fiber shirts is far less expensive than the upkeep of any other naturalfiber garment in current production. D. While producers anticipate that the cost of microfiber synthetics will remain stable, they recognize that the advent of recycling programs for natural fibers should bring down the costs of natural fibers. E. The cost of providing stain guards for microfiber synthetic shirts would probably be greater than what garment producers now spend on stain guards for natural-fiber shirts.