The parking brake should not have which of the following conditions?

The parking brake should not have missing, broken, badly worn, or not operating properly parts because these conditions directly affect the functionality and safety of the parking brake system. A properly functioning parking brake is essential for keeping the vehicle stationary when parked, especially on inclines. If any components are missing or damaged, the effectiveness of the parking brake is compromised, which could lead to the vehicle rolling unexpectedly and potentially causing accidents or injuries.

In contrast, while stretched cables, excessive friction material, and corroded components may present issues, the presence of missing or broken parts is a more critical failure that fundamentally prevents the parking brake from functioning as intended. Addressing the latter condition ensures reliability in the vehicle's parking mechanism, which is paramount for safety.