Anastasia is marketing and selling complementary goods
A complementary goods go hand in hand. In other words these type of goods usually sell together and complememt each other.
Anatasia sells complementary goods since she sells goods related to the concert. For example, she could sell popcorns for a movie at the concert.
Complementary goods go together, even with price. An increase or decrease in the price or quantity of one will bring about the increase or decrease in price or quantity of the other.
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https://brainly.com/question/1338465