The size of a landform on the Earth's surface can vary significantly, but in the context of classification based on size, landforms are typically categorized into various segments. Given the options and understanding how landforms are generally perceived, they can belong to different classes such as:
- Smallest part, which may refer to minor features like a hillock or a small dune.
- Small to medium part, which could include features such as hills, small plateaus, or basins.
- Medium part, representing features like large hills or small mountain ranges.
- Medium to largest part, indicating more extensive features such as large mountain ranges or vast plateaus.
The correct classification from the provided options is indeed small to medium part. This reflects typical landforms like hills or small plateaus that have measurable but not exceedingly large physical dimensions when compared to the largest formations like continents or large mountain ranges.