Which of the following best defines 'Operating expenses'?

Operating expenses refer to the costs that a business incurs during its normal course of operations. These expenses are essential for maintaining the day-to-day activities of the organization and include items such as rent, utilities, salaries, and administrative costs. These costs do not directly relate to the production of goods or services, which is why they differ from expenses related to the cost of goods manufactured.

The focus on daily operations highlights that operating expenses are recurring costs that must be accounted for in order to maintain the business’s functionality. This distinction is crucial for understanding a company's income statement, as operating expenses are subtracted from revenue to determine operating income.

The other options, while related to financial concepts, do not accurately define operating expenses. Costs of goods manufactured pertain to production costs, not operational costs. Income generated before taxes reflects profitability but does not specify how expenses are categorized within that context. Revenue from sales refers to the income generated from selling goods or services, which is separate from the operating costs necessary to conduct business activities.