You are using the Knowledge Discovery feature of the Data Quality Services (DQS) client application to modify an existing knowledge base. In the mapping configuration, two of the three columns are mapped to existing domains in the knowledge base. The third column, named Group, does not yet have a domain. You need to complete the mapping of the Group column. What should you do?
A. Map a composite domain to the source column.
B. Create a composite domain that includes the Group column.
C. Add a domain for the Group column.
D. Add a column mapping for the Group column.