You have created a composite report and are trying to add a matrix report as...

For amatrix report to be used as a subreportin a composite report, the group-by fields in the matrix report must align with the fields enabled for filtering and grouping in the composite report. If this alignment does not exist, Workday does not allow the matrix report to appear as a valid subreport option in the Sub Report Name dropdown.

From the Workday binder:“To include a matrix report as a subreport in a composite, the group-by fields of the matrix must match the fields enabled for grouping in the composite report. If these do not match, the matrix will not appear in the Sub Report Name selection.”

Other factors such as prompt defaults or filter settings may impact usability, but they do not prevent the matrix report from being selectable. The key dependency is thefield alignment between the composite and the matrix group-by fields.

Therefore, the correct answer isA. Check that every field in the composite report's set of fields that are enabled for filtering and grouping also exists as a group-by field in the matrix report.