Answer:
C. Product differentiation
Explanation:
-Rivalry refers to the competition between people or organizations when they have the same goal.
-Buyer power refers to the situation in which customers are able to have influence on things like quality and prices of the products offered by companies.
-Product differentiation refers to trying to differentiate a product or service from its competition to make it more attractive for the customer.
-Substitute product is a good that can be used instead of another one.
According to this, Amazon is using product differentiation to achieve this competitive advantage as it is offering products tailored to a particular customer which is an effort to make the product distinguish from the similar ones and get the customer to buy it.
