can B be considered as a prime attibute?

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+9 votes

Answer : C

Third Normal Form but not BCNF

See the dependencies

AB ---> CDE

C ---> B

C is not a Super key Here

+5 votes

AB is the key here which determines C ,D E there is no P.D and T.D between C,D,E SO IT IS IN 3NF

Now for BCNF every determinant is a candidate key determinant here are A,B,C (as C determines B) but C is not candidate key hence it is not in BCNF (only if C->B is removed it becomes BCNF)

AC is also key which can determine B and so also D , E but B is not candidate key

hence ans is C

Now for BCNF every determinant is a candidate key determinant here are A,B,C (as C determines B) but C is not candidate key hence it is not in BCNF (only if C->B is removed it becomes BCNF)

AC is also key which can determine B and so also D , E but B is not candidate key

hence ans is C

+4 votes

Answer : **C**

**Dependency: **

AB ---> CDE

C ---> B

**1NF(yes): **assume all attributes are atomic

**2NF(yes)**: no partial functional dependency like A alone can derive C or D or E

**3NF(yes)**: no transitive functional dependency or there is nothing like (non key)-->(non key)

**BCNF(no)**: in non trivial FD C-->B , C is not a SuperKey.

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