Answers A and E are correct. A JOIN operation is needed to return related items from two or more tables. To perform a comparison against NULL data, you use the ISNULL operation. A UNION could return results from two tables but does not relate the data. BETWEEN is used to test whether a value falls within a given range, and you use IN to see if a value falls within a set of values provided.
For more information, see the following sources:
Chapter 3, "Implementing Database Objects"
SQL Server 2005 Books Online: "SQL Server Database Engine, Accessing and Changing Database Data, Query Fundamentals, Join Fundamentals"
SQL Server 2005 Books Online: "SQL Server Language Reference, Transact-SQL Reference, ISNULL"
"Using Inner Joins," http://msdn2.microsoft.com/en-us/library/ms190014(SQL.90).aspx
Within MSDN Library, go to MSDN Home, MSDN Library, Enterprise Servers and Development, SQL Server, SQL Server 2005 Documentation, SQL Server 2005 Books Online, SQL Server Database Engine, Accessing and Changing Database Data, Query Fundamentals, Join Fundamentals, Using Joins, Using Inner Joins.