Answer:
Pepsi and Coca Cola are considered a duopoly because they hold a dominant market share in the soda industry.
Together, they control more than 70% of the soda market.
They have been competing with each other for over a century and have developed strong brand recognition worldwide.
Due to their size and influence, they can also set prices, affect the demand for other beverages, and make it difficult for new competitors to enter the market.