1. A final decree of adoption may not be issued and an interlocutory decree of adoption does not become final, until the minor to be adopted, other than a stepchild of the petitioner, has lived in the adoptive home:
a. For at least six months after placement by an agency;
b. For six months after placement by a parent in accordance with an identified relinquishment under chapter 14-15.1;
c. As a foster child for at least six months and has been placed for adoption by an agency; or d. For at least six months after the department and human service zone or the court has been informed of the custody of the minor by the petitioner, and the department and human service zone or the court has had an opportunity to observe or investigate the adoptive home.
2. If a child who has been placed for adoption dies before the six-month residency requirement of subsection 1 is met, the court may grant the final decree of adoption upon a finding that a proper and legitimate reason exists for granting the final decree.