A notice under this Act shall be deemed to have been served on or given to any person—
(a) if served on him or her personally;
(b) if served on an attorney holding a power of attorney whereunder such attorney is authorised to accept service;
(c) if sent by registered post to him or her at his or her last known postal address in the State or elsewhere and a receipt purporting to have been signed by him or her has been received in return; or
(d) if service cannot be effected in one of the abovementioned ways, by displaying it in a prominent place on the land affected for a period of 3 weeks and by 2 publications in a local newspaper.