4.—Where a notice, direction or other document is authorised or required by or under this Act or regulations made thereunder to be served on a person, it shall, unless otherwise specified in this Act, be addressed to the person and shall be served on or given to the person in one of the following ways—

(a) where it is addressed to the person by name, by delivering it to the person, or

(b) by leaving it at the address at which the person ordinarily resides or, in a case in which an address for service has been furnished, at that address, or

(c) by sending it by ordinary prepaid post addressed to the person at the address at which the person ordinarily resides, or in a case in which an address for service has been furnished, at that address.