What permissions are needed to edit labels in the system?

To edit labels in the system, "View Sources and Review and Label" permission is necessary because this permission includes the capability to access the sources where the labels are applied as well as the ability to review and make modifications to those labels. It allows users not only to see what is labeled but also to participate in the labeling process itself, facilitating changes or updates to existing labels based on new insights or data corrections.

The other options focus on individual aspects of permissions. "View Labels" only provides access to see the labels without offering editing capabilities. "Edit Sources" pertains to modifying the data sources themselves rather than the labels that are applied to those sources. "Train Models" relates to the process of training machine learning models but does not directly involve the editing of labels. Therefore, the comprehensive nature of the "View Sources and Review and Label" permission makes it the correct choice for enabling edits to labels.