You have to design a new database, the tables in the database should be replicated to three offices and the database tables should have the following requirements :

+ a unique row should be identified among all the rows
+ the row should be unique among the entire organization.

What option should you use?

A.
add a new column that have the identity property.

B.
add a new column that have the hierarchyid datatype.

C.
add a new column with a uniqueidentifier datatype and put the default to the getdate().

D.
add a new column with a uniqueidentifier datatype and put the default to the NEWID().

Explanation:
http://msdn.microsoft.com/en-us/library/ms190348.aspx