Final answer:
Sheryl's law firm is involved in a producer market when buying office products, which classifies as firms purchasing in the goods market.
Step-by-step explanation:
The type of market Sheryl's law firm is participating in when it buys office products for its own use can be categorized as a producer market. In this context, the firm is acting as a buyer in the marketplace where firms purchase goods and services that are necessary for their operations, which is different from a consumer market, where households purchase items for personal use.
The law firm's activities align with firms in the goods market, as they are acquiring products to support their business processes, not for direct resale.
The type of market where a law firm buys office products which are used by the firm is a Producer market. In a producer market, businesses purchase goods and services that are used in the production process. As a law firm, Sheryl's firm is purchasing office products for internal use, which aligns with the characteristics of a producer market.