Final answer:
A 'wheeled fire extinguisher' is a type of fire extinguisher with built-in wheels for easy transport, primarily used in settings where large fires might occur and a substantial amount of extinguishing agent is necessary.
Step-by-step explanation:
The term 'wheeled fire extinguisher' refers to option a, an extinguisher with a built-in wheel for easy transport. These types of extinguishers are typically larger than handheld units and are intended for use in situations where a significant amount of extinguishing agent is needed. They can be found in places such as industrial sites, airports, or large commercial buildings where a fire with substantial fuel could occur.
The defining characteristic of a wheeled fire extinguisher is its mobility. The wheels allow for a single individual to maneuver the extinguisher quickly to the location of a fire, which is crucial in emergency situations. Despite their larger size, they are designed to be user-friendly and can be a vital asset during a fire emergency.