This query is typically used by business managers to evaluate data in the tables of an existing database system that is maintained by their firm's IT departments:

Create the list of all professors who ever taught MAT123. The information must include all attributes available from the Professor relation.

Using the document structure described in Exercise 15.23, formulate the following queries in XQuery:

The ____ class retrieves realm information for SaslClient and SaslServer.

A. ChoiceCallback B. RealmCallback C. LanguageCallback D. AuthorizeCallback