BCNF :-
1.IF X----->Y (then X is either Super key or Candidate Key).
2.LHS is super key(For every dependency)
3. it should be in the 3NF.
3NF-
X--------->Y
1.X is super key
OR
2.Y is prime Attribute.
now given question,
R(A,B,C)
AB----->C
C------>A CANDIDATE KEY---(AB)
PRIME ATTRIBUTE --(A,B)
BCNF :-
AB----->C (then AB is either Super key or Candidate Key). (CORRECT)
C-------->A (then C is either Super key or Candidate Key). AND (A IS PRIME ATTRIBUTE ) ( NOT CORRECT)
Go for 3nf
AB----->C (then AB is either Super key or Candidate Key). (CORRECT)
C-------->A (then C is either Super key or Candidate Key). OR (A IS PRIME ATTRIBUTE ) ( CORRECT)
SO the given functional dependencies: is 3NF, NOT BCNF