Which of the following describes a folding ladder?

A folding ladder is specifically designed for ease of storage and transport, making option B the correct description. Its foldable nature allows it to collapse into a compact size, which is particularly useful for fire departments or individuals who may need to store the ladder in a confined space or vehicle. This design enhances versatility, as it can be easily deployed and retracted without requiring extensive handling.

The other choices describe different types of ladders that do not match the characteristics of a folding ladder. A continuous extending ladder denotes a ladder that can be lengthened but does not fold for storage. A two-section ladder consists of two parts that slide regarding each other but do not necessarily have the compact folding capability. A straight single-piece ladder refers to a fixed-length ladder that cannot be adjusted or folded, emphasizing stability over portability.