You have two tables named dbo.CurrentProducts and dbo.ArchiveProducts. You have the following
query:
SELECT ProductID, Name
FROM dbo.CurrentProducts
UNION ALL
SELECT ProductID, Name
FROM dbo.ArchiveProducts;
You need to predict the list of products that the query will produce.
Which list of products should the query return?
A.
 Products that appear in dbo.CurrentProducts or dbo.ArchiveProducts but not in both.
B.
 Products that have a matching ProductID and Name in dbo.CurrentProducts or 
dbo.ArchiveProducts.
C.
 Products that appear in dbo.CurrentProducts or dbo.ArchiveProducts. Products that appear in 
both 
tables are listed only once.  
D.
 Products that appear in dbo.CurrentProducts or dbo.ArchiveProducts. Products that appear in 
both 
tables are listed multiple times.