Correct Response: B. The environmental conditions are controlled, and the comparison stated is correct and sufficient to answer the question as to which plastic degrades more quickly. A is incorrect because the two plastics are not compared and degradation rates are theoretical. C is incorrect because degradation rates provided by the manufacturer may be biased and also because the degradation rates of the two types of plastic were likely measured using different environmental conditions. D is incorrect because the experiment in this option only involves one type of plastic.