The text begins with an explanation of the term product life cycle. After the explanation is provided, the text seems to go on to provide numbers of comparisons of the product life cycle. Evidence: "During the first stage—growth—the product is being developed much as a human develops from infancy to, say, young adulthood." This excerpt from the text compares the growth of a product to the growth of an infant. Thus, you can conclude that the correct option is b. comparison.