What type of equipment is described as having extension arms that are recessed within one another?

The correct choice refers to boom lifts, which are designed with extension arms that can be retracted or extended. These arms are often housed within one another, allowing the lift to maintain a compact form when not extended. This feature is beneficial in situations where space is limited, as it allows for easy maneuverability and transportation.

Boom lifts are versatile pieces of equipment used for reaching high places, typically equipped with a bucket or platform at the end of the extending arm, enabling workers to safely perform tasks at elevation. The ability to retract the arms helps in reducing the overall footprint of the machinery, making it easier to position and navigate in tight areas, which is a key function of this type of equipment.

While scissor lifts, forklifts, and cherry pickers have unique features suited for their specific tasks, they do not possess the same retractable arm design that characterizes boom lifts. This distinct feature of boom lifts enhances their practicality in urban and construction environments where height access and space constraints are often crucial factors.