Which of the following is NOT an acceptable condition for a windshield during a pre-trip inspection?

The answer is "D" because a windshield that is bent does not meet the acceptable condition required for safe operation of a vehicle during a pre-trip inspection. A bent windshield can compromise the integrity of the glass and could affect the driver's visibility, increasing the risk of accidents. During a pre-trip inspection, the windshield must be inspected to ensure it is not only free from cracks and breaks but also properly shaped and securely mounted to maintain structural integrity and visibility.

In contrast, the other choices highlight positive conditions necessary for a windshield to be considered safe. A windshield that is not cracked or broken is essential to ensure that there are no obstructions in the driver's line of sight. Additionally, a securely mounted windshield is crucial to prevent it from coming loose while driving, which could be dangerous. Therefore, "D" is the correct choice as it indicates a condition that is unacceptable during the inspection.