What should be true about panel mirrors and their brackets?

The correct choice emphasizes that the panel mirrors and their brackets must be secure, free from damage, and that there should be no loose or missing nuts, bolts, or fittings. This is crucial for several reasons:

First, secure mirrors are vital for the driver's visibility and safety. Any instability could lead to misalignment or detachment while driving, posing hazards not only to the driver but also to other road users.

Second, the absence of damage ensures that the mirrors can provide a clear view, allowing the driver to monitor traffic and surroundings effectively. Damaged mirrors can obstruct visibility and increase the risk of accidents.

Lastly, having all necessary fittings intact is essential for maintaining the structural integrity of the mirrors. Missing fittings can compromise the mirror's functionality, and loose components might lead to further deterioration or failure over time.

The other options do not reflect the necessary safety and operational standards for panel mirrors and their brackets, making them unsuitable for a thorough pre-trip inspection.