Answer:
b. price
Explanation:
In the context, Tina is an expert in marketing and she analyzed the competitive cost of the landscape of the textbooks that target customers uses them to evaluate the value of the book and the amount will pay. Here Tina is evaluating the price area of the 4P marketing mix.
The marketing mix is defined as the foundation model for the businesses that centered around the the product, promotion, price and place. They are known as the four Ps in the marketing mix.