The process by which nylon is manufactured releases large amounts of the gas nitrous oxide, which is harmful to the environment. Since the processing of cotton fiber does not release environmentally harmful gases, there would be less environmental damage done if cotton fiber rather than nylon were used to make products such as thread and rope. Which one of the following, if true, would weaken the argument? ['Even if the quantity of nitrous oxide released into the environment decreased, many environmental problems would remain unsolved.', 'If cotton fiber replaced nylon in the production of thread and rope, there would be a resulting increase in the amount of nylon used in other manufactured products.', 'If the quantity of nylon manufactured annually decreased substantially, the volume of several pollutants that are released into the environment during its manufacture would be reduced.', 'Even if only some of the thread and rope that is currently being made from nylon were instead made from cotton fiber, some environmental damage would be avoided.']