What is true regarding the exterior stairs in a NLT building?

The statement that exterior stairs in a Non-Lightweight (NLT) building provide access to the cellar, which has a fireproof ceiling, is accurate because NLT buildings are constructed to include fire-resistant materials, particularly in areas like the ceiling of the cellar. This feature is essential for maintaining safety during a fire situation, as it helps to contain any potential fire in the cellar and prevents it from spreading to upper floors.

The construction regulations for NLT buildings ensure that these cellars are designed with safety in mind, which includes fireproof ceilings that can withstand heat for longer periods. This is crucial for maintaining the structural integrity of the building during a fire and providing a safer environment for both residents and firefighters.

In contrast, the other options do not accurately convey the functions and characteristics of exterior stairs in NLT buildings. While they might be used for emergency access, they are not limited to emergency use only and serve multiple purposes. Understanding the fire safety features of NLT buildings, especially regarding their stairways and cellar design, is vital for effective firefighting and rescue operations.