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Consider the following relational schema:
Suppliers(sid:integer, sname:string, city:string, street:string)Parts(pid:integer, pname:string, color:string)Catalog(sid:integer, pid:integer, cost:real)
Consider the following relational query on the above database:
SELECT S.sname FROM Suppliers S WHERE S.sid NOT IN (SELECT C.sid FROM Catalog C WHERE C.pid NOT IN (SELECT P.pid FROM Parts P WHERE P.color<> 'blue'))
Assume that relations corresponding to the above schema are not empty. Which one of the following is the correct interpretation of the above query?
(A) Find the names of all suppliers who have supplied a non-blue part.
(B) Find the names of all suppliers who have not supplied a non-blue part
(C) Find the names of all suppliers who have supplied only non blue parts.
(D) Find the names of all suppliers who have not supplied only non-blue parts.
nan