“exchange item” of or in relation to a person means an amount in a foreign currency-

 

(a)     which constitutes any unit of currency acquired and not disposed of by that person;

 

(b)     owing by or to that person in respect of a debt incurred by or payable to such person;

 

(c)     owed by or to that person in respect of a forward exchange contract; or

 

(d)     where that person has the right or contingent obligation to buy or sell that amount in terms of a foreign currency option contract.