Final answer:
Expanding a cafe's physical space is an example of a long-run adjustment because it involves changes to the fixed assets and long-term operational scale, unlike short-term changes such as menu pricing or staffing.
Step-by-step explanation:
Among the options provided, an example of a long-run adjustment for the owners of a small cafe would be c) Expanding the cafe's physical space. This adjustment implies a substantive change to the fixed assets of the business, which aligns with the definition of long-run adjustments where all factors of production are variable. Adjustments such as changing daily specials, hiring additional staff, and tweaking menu prices often fall under short-term operational changes, whereas expanding the physical space of the cafe indicates a strategic decision made with the long-term growth of the business in mind. It involves evaluating market conditions, committing capital investment, and potentially altering the scale of operations once their lease agreement period allows re-evaluation and change.
The concept of 'menu costs' is related to the idea that changing prices can incur expenses and customer dissatisfaction; however, this is not considered a long-run adjustment as it's more associated with short-term pricing strategies and operational decisions. In macroeconomics, shifting all prices throughout the economy to reflect supply and demand is a process that takes time, indicating that menu costs are a consideration within the short to medium term.