Final answer:
The term that corresponds to 'regular expenses' in the provided context is 'Fixed costs,' which are unchanging expenses regardless of production levels. Option 5.
Step-by-step explanation:
The question given revolves around understanding specific terminology related to history and economics. The term that best fits the definition of 'regular expenses' from the provided list is 'Fixed costs' option 5. This term is used to describe expenses that do not change with the level of goods or services produced by a business, such as rent, salaries, and insurance. These costs are generally time-related and contrast with variable costs, which can fluctuate with production output.