$5.$ What are some of the key product decisions? Explain$\mathrm{.}6.$ List the stages of the product life cycle$\mathrm{.}7.$ What are some rejuvenating strategies for expanding the product life cycle? Explain$\mathrm{.}8.$ What is adoption? List the different stages$\mathrm{.}9.$ List and explain the adoption categories.