Given a first normal form relation SECOND with attributes A, B, C, D, E, and the functional and multi-valued dependencies as well as the functional and the multi-valued dependency diagram as follows:

SECOND

A

B

C

D

E

Functional Dependencies {AB → C, C → B}

Multivalued Dependencies {C →→ D, C→→ E}

Dependency Diagram

What is the key in SECOND? 

What is the highest normal form this relation is in? 

Normalize SECOND into BCNF by giving its relation names, their attributes with primary keys underscored and foreign keys pointing to the corresponding attributes properly and its dependency diagrams as showing above. 

Normalize the result in question 3 into the fourth normal form by giving its relation names, their attributes with primary keys underscored and foreign keys pointing to the corresponding attributes properly and its dependency diagrams.