The concept of product life cycle is based on few key assumptions. They are:

A. Products have a limited life

B. Product sales pass through distinct stages, each passing different challenges, opportunities and problems to the seller.

C. It occupies most desirable position in consumer's mind making the brand almost impregnable. 

D. It erects outposts to protect a weak front or support a possible counterattack. 

E. Profits rise and fall at different stages of the cycle.

Choose the correct answer from the options given below: