Breadcrumb navigation appears in the document viewer after which analytics operations?

Breadcrumb navigation appears in the document viewer after the "Find Similar Documents" operation because this feature is specifically designed to indicate the user's path and the results of their search for related documents. When users utilize the "Find Similar Documents" functionality, they often seek to explore content that shares characteristics with a specific document, leading to a hierarchical display of that exploration path. Breadcrumbs help users navigate back to their original document or previous steps in their exploration process efficiently.

In contrast, the other operations listed do not inherently support a navigational hierarchy in the same manner. "Active Learning" focuses primarily on training models based on user feedback, while "Keyword Expansion" and "Concept Search" are aimed at enhancing search capabilities rather than tracking the user’s journey across documents. Therefore, breadcrumbs are specifically applicable to situations where users examine similar documents, making this the correct answer.