• Sergiy (1/12/2012)


    Explanation:

    Nothing is stopping an INDEX SEEK from being used and answer "A" is the correct answer.

    Actually something does.

    It's named "bookmark lookup".

    There is no 'bookmark lookup' in this case as Jeff's explanation of point H reveals: the non-clustered index is covering for the query.

    'Bookmark lookup' is out-of-date now: they are referred to as an RID Lookup for a heap, or Key Lookup for a clustered index. The lookup operation is a seek on the clustered index key, or direct navigation to a row locator (RID) if the base table is a heap.