Answer is $C$.
Generally Normalization is done on the schema itself.
From the relational instance given,we may strike out $FD$ s that do not hold.
E.g. $B$ does not functionally determine $C$ (This is true).
But, we cannot say that $A$ functionally determines $B$ for the entire relation itself. This is because that, $A->B$ holds for this instance,but in future there might be some tuples added to the instance that may violate $A->B$.
So, overall on the relation we cannot conclude that $A->B$, from the relational instance which is just a subset of an entire relation.