Final answer:
The correct answer to the question is Microeconomics, which examines the economic decisions and pricing strategies of individual business firms.
Step-by-step explanation:
The study of how a single business firm sets its prices would fall under the study of Microeconomics. Microeconomics is the branch of economics that focuses on the behavior and decision making processes of individual firms and households. In microeconomics, various elements such as consumer behavior, the theory of the firm, market operations for labor and resources, and market efficiencies are examined. These elements are crucial in determining the prices a firm will charge, production methods, the number of workers to hire, business financing, and decisions related to business expansion or contraction.