Which of the following statements about the characteristics of relict nodules is correct?

Relict nodules are typically rounded due to the natural processes of weathering and erosion that affect them over time. The rounded shape is a result of the dissolution of surrounding materials and the transport processes that smooth their edges. This characteristic is important for identifying and understanding the formation processes of these nodules within soil profiles.

In contrast to the rounded shapes of relict nodules, sharp-edged nodules would suggest more recently formed or less weathered materials, which is not a characteristic of relict nodules. The notion that they are only found in ancient soils is overly restrictive, as such nodules can be present in various soil types depending on their formation history. Additionally, relict nodules do possess a defined shape; their typical rounded form is one of the key properties that aid in identification.