Which of the Following Is Correct with Respect to Porter's

Multiple Choice

Which of the following is correct with respect to Porter's Five Forces model?

A) Rivalry among existing firms is the most important element in the model.
B) When there are many substitute products available,the industry is less competitive.
C) When there are only a few suppliers in an industry,buyers have less power.
D) When substitute products are available,suppliers have more power.
E) All of these statements are correct.