(1) In relation to a gift taken under a disposition, where the date of the disposition is before 1 December 1999, "taxable gift" in this Act means -

(a) in the case of a gift, other than a gift taken under a discretionary trust, where the disponer is domiciled in the State at the date of the disposition under which the donee takes the gift, the whole of the gift,

(b) in the case of a gift taken under a discretionary trust where the disponer is domiciled in the State at the date of the disposition under which the donee takes the gift or at the date of the gift or was (in the case of a gift taken after that disponer's death) so domiciled at the time of that disponer's death, the whole of the gift, and

(c) in any other case, so much of the property of which the gift consists as is situate in the State at the date of the gift.