Because chemical fiber is artificially synthesized from petroleum and other raw materials, the production of chemical fiber will produce many pollutants, it will use a lot of energy and water, and the chemical fiber garbage will degrade slowly in the natural environment. Chemical fiber is more environmentally friendly. Which of the following, if true, would pose the strongest doubt about the above view? ['The latest chemical fiber has no obvious difference from pure cotton fabrics in appearance, feel, and moisture absorption.', 'Scientists are studying new ways to recycle, utilize, and dispose of chemical fiber waste.', 'The price of cotton fabrics is relatively high, and the working class and farmers, who account for the majority of the population, cannot afford to wear them.', "Cotton is the most used agricultural crop, and 25% of the world's pesticides are used for cotton cultivation."]