A term describing a firm's normal range of operating activities is: (a) Relevant range of operations. (b) Break-even level of operations. (c) Margin of safety of operations.

A firm's normal range of operating activities is relevant range of operations.

Explanation:

Relevant range of operations can be described simply as a firm or company's expected range of activities without any extreme economic conditions. It is the range where the firm operates in normal conditions. Within this range the firm's operations run smoothly. Outside this range revenue and expenditure may fluctuate from what was expected.