Finding the candidate key

Question

I have a relation R(A,B,C,D,E,G,H) which the functional dependencies :

AB -> CD

E -> D

ABC -> DE

E -> AB

D -> AG

ACD -> BE

H is not dependant on anything but its not in the dependencies.

My question is that is {HE} the candidate key as {HE}+ = R?

OR

E is the candidate key because {E}+ = R

Answer 1

{CDH}{HE}{ABH}{BDH}

are the candidate keys. So indeed, HE is Candidate Key, but not the only one who determines the hole Relation. Seeing the functional dependencies it is in the first normal form (1NF)