When Looking at the Entire Industry,the Main Areas in a Company's

When looking at the entire industry,the main areas in a company's overall value chain where important differences between a firm's cost and value do not occur are in

A) a company's own internal activities.
B) the supplier's industry value chain.
C) the forward channel portion of the industry chain.
D) a company's own internal activities,the supplier's industry value chain,and the forward channel portion of the industry chain.
E) a company's external activities,the supplier's part of the industry value chain,and the buyer's ability to integrate backward.