Porter's "Five Forces Model" for Industry Analysis Recommends an Analysis

Porter's "five forces model" for industry analysis recommends an analysis of the________

A) competitive threat of similar products on the market and of other products that may substitute for the business plan's product.
B) rivalry among current firms in the industry but not of potential new entrants.
C) bargaining leverage of the industry's suppliers and of its customers.
D) both a and c
E) both b and c