The concept of product life cycle is based on which of the following key assumptions?

A. Profits remain stable at different stages of product life cycle

B. Products have an unlimited life

C. Product sales pass through distinct stages, each posing different challenges, opportunites and problems to the seller

D. Products require different marketing, financial, manufacturing, purchasing and human resource strategies in each of the life cycle stages

E. Products have a limited life

Choose the most appropriate answer from the option given below: