Which item is a ladder type among the choices?

• A. Rope ladder
• B. Platform ladder
• C. Extension ladder
• D. Stool ladder

Answer: (C)

The idea being tested is recognizing a ladder designed to change its length to reach different heights. An extension ladder is built with two or more sections that can telescope or slide out, allowing the user to extend to higher elevations and then lock at the desired length for stability. This extendable feature is what defines it as a ladder type. The other options describe ladders that are fixed in length or serve different forms—rope ladders are flexible and not the same as a rigid, extendable ladder, platform ladders are fixed-height with a standing platform, and stool ladders aren’t a standard ladder category used for reaching heights. So the extendable ladder fits the concept of a ladder type that adjusts for height.