Which of the following is not a condition for rejecting seat belts?

The condition that indicates a seat belt is completely functional is identified as the correct answer. This means that if a seat belt is fully operational, it meets safety standards and should not be rejected during an inspection. A completely functional seat belt will retract properly, show no signs of wear or damage, and have a working release mechanism, ensuring both safety and compliance with inspection criteria.

In contrast, the other conditions mentioned—such as a retraction mechanism being inoperative, frayed or torn fabric, and release mechanisms being inoperative—are all indications of potential failures or issues that compromise the effectiveness of the seat belt. These conditions would warrant the rejection of the seat belt during an inspection, as they can significantly affect passenger safety in the event of a collision.