Explanation:

- Option 1: MC Curve (Marginal Cost Curve)

- Marginal cost considers the additional cost of producing one more unit of output.

- It fluctuates with changes in variable costs, not fixed costs.

- Correct Answer: The MC Curve is not affected by fixed costs.

- Option 2: TC Curve (Total Cost Curve)

- Total cost equals fixed costs plus variable costs.

- An increase in fixed costs shifts the TC curve upward.

- Option 3: AC Curve (Average Cost Curve)

- Average cost combines fixed and variable costs divided by output.

- Changes in fixed costs alter the AC curve.

- Option 4: AFC Curve (Average Fixed Cost Curve)

- Average fixed cost decreases as output increases.

- It is directly tied to fixed costs.