A functional dependency X → Y is a full functional dependency if removal of any attribute A from X means that the dependency does not hold any more; that is, for any attribute A ε X, (X – {A}) does not functionally determine Y.
A functional dependency X → Y is a partial dependency if some attribute A ε X can be removed from X and the dependency still holds;
Here if we remove B from AB→C
We get A→C (as A→C holds bcz it is in fd already)
If we remove B From there AB→C can't hold any more C fully depends on A.
So C partially depends on AB and AB→C is partial fd
Read answer of philipxy or his replies ovr the comment carefully.