Which of the following statements about the product life cycle (PLC) is true? Select one: O a. The PLC concept encourages marketing managers to think reactively, O b. Marketers do not yet understand the relationship between the adopter categories and the stages of the PLC. O c. There are as many new buyers in the maturity stage of the PLC as in the growth stage. Od. The PLC is especially useful as a predicting tool. e. Just as there are five adopter categories, there are five PLC stages