Answer: THREAT OF SUBSTITUTE PRODUCTS.
Explanation:Porter's model was developed by a Harvard business school Lecturer known as Michael E. Porter in 1979. Michael E. Porter developed a Five Forces model that identifies and analyzes five competitive forces that shape every industry, and determines an industry's weaknesses and strengths.
The five competitive forces are as follows;
COMPETITIVE RIVALRY which determines the strength and number of your competitors.
SUPPLIER POWER which determines the uniqueness of the supplies given to you by your suppliers and the number of suppliers you have etc.
BUYER POWER which evaluates how many buyers you have,how easy it is for them to buy your products etc.
THREAT OF SUBSTITUTION which evaluates how easy it is for your buyers to buy another substitutes to your product etc.
THREAT OF NEW ENTRY which evaluates the ability or easy access of new products to penetrate the market,how well you are to maintain your strength etc.
