Understanding Fixed Costs in Economics

Steps:

• Recall that fixed costs do not vary with output levels but remain constant up to a certain production range.
• Evaluate choice A: It mixes fixed and variable elements, which describes semi-variable costs, not pure fixed.
• Evaluate choice B: This fits variable costs, which change per unit with output.
• Evaluate choice C: Fixed costs are constant in total, but only within limits; beyond that, they may step up.
• Select D as it specifies the "relevant range," aligning with standard accounting definitions.

Why D is correct:

• Fixed costs remain unchanged in total for output levels within the relevant range, per cost accounting principles.

Why the others are wrong:

• A: Describes mixed costs, not fixed.
• B: Applies to variable costs, constant per unit but total varies.
• C: Ignores the relevant range limitation, making it overly absolute.

Final answer: D