To assess the specific textual differences within a near duplicate group, Relativity Compare is the appropriate tool. After running a textual near duplicate analysis, users can view the group members in the related items pane. From there, they can select two documents and use the compare function to see a side-by-side view with redlines highlighting the exact variations in text. This allows for a precise assessment of how the documents differ, which is the core of the question.

B. Image QC is a tool for reviewing the quality of document images (e.g., for clarity or missing pages), not for comparing extracted text.

C. Document View Overlay is not a standard Relativity tool. The term "overlay" refers to updating existing records with new data, not comparing text.

D. The Similar Documents View displays the list of documents in a near duplicate group but does not, by itself, show the differences between them.

1. Relativity Documentation. (n.d.). Running a structured analytics set. Retrieved from Relativity Community. Section: "Textual near duplicate identification results". (This section explicitly mentions using the compare function to see the differences between near duplicates).

2. Relativity Documentation. (n.d.). Viewers. Retrieved from Relativity Community. Section: "Relativity Compare".