The notice referred to in Sections 921.03  and 921.04 shall be sufficient and shall be deemed to have been given when a written notice is:
   (a)   Delivered in person; or
   (b)    Deposited in the United States mail addressed to the owner at his address as the same appears in the records of the City; or
   (c)    When such notice is posted on the lot, tract or parcel of land referred to in this article.