Among common plotter types, the drum plotter effectively eliminates media length limitations by feeding paper around a rotating drum, allowing extremely long continuous plots beyond fixed page sizes.

Introduction / Context:
Large-format plotting can be constrained by the physical size of the media. Different plotter mechanisms handle media in different ways, which affects maximum drawing size. Knowing which mechanism avoids page-length limits helps in selecting equipment for GIS, CAD, and mapping applications requiring very long plots.

Given Data / Assumptions:

• Some jobs require continuous long-axis output (e.g., seismic logs, long profiles).
• Mechanism of media transport determines size limitations.
• We compare drum, flatbed, electrostatic, and pinch-roller designs.

Concept / Approach:
A drum plotter mounts paper on a rotating drum and advances it continuously while the pen moves along the orthogonal axis. As long as the paper roll is sufficiently long, the plot length can be effectively unlimited. Flatbed plotters are constrained by bed dimensions; electrostatic devices can be roll-fed but the question emphasizes plotter mechanisms; pinch-roller mechanisms still typically depend on sheet or roll sizes with more practical limits than classic drum transport.

Step-by-Step Solution:
Identify the mechanism that allows continuous media feed.Recognize drum plotter operation with paper wrapped on a rotating cylinder.Infer that plot length is limited only by roll length, not bed size.Select “Drum.”

Verification / Alternative check:
Historical specifications for drum plotters highlight long plotting capability for engineering and scientific applications, confirming their advantage for lengthy drawings.

Why Other Options Are Wrong:
Flatbed: limited by the physical bed dimensions.Electrostatic: describes imaging method, not necessarily eliminating size limits in plotter context.Pinch roller: transport method still tied to practical media limits and not known for “unlimited length.”None of the above: incorrect because drum is correct.

Common Pitfalls:
Confusing imaging technology (electrostatic) with media transport; assuming all roll-fed devices eliminate size limits without considering mechanism specifics.

Final Answer:
Drum