Normalization & Functional Dependencies

Statement for linked answer Q.54 and Q.55: Relation R has eight attributes ABCDEFGH. Fields of R contain only atomic values. $F = \{CH \to G,\ A \to BC,\ B \to CFH,\ E \to A,\ F \to EG\}$ is a set of functional dependencies (FDs) so that $F^+$ is exactly the set of FDs that hold for R. How many candidate keys does the relation R have?

Statement for linked answer Q.54 and Q.55: Relation R has eight attributes ABCDEFGH. Fields of R contain only atomic values. $F = \{CH \to G,\ A \to BC,\ B \to CFH,\ E \to A,\ F \to EG\}$ is a set of functional dependencies (FDs) so that $F^+$ is exactly the set of FDs that hold for R. The relation R is