N.C. Gen. Stat. § 48-3-704
In addition to the mandatory provisions listed in G.S. 48-3-703, a relinquishment may also state that the relinquishment may be revoked upon notice by the agency that an adoption by a specific prospective adoptive parent, named or described in the relinquishment is not completed. In this event the parent's time to revoke a relinquishment is 10 days, inclusive of weekends and holidays, from the date the parent receives such notice from the agency. The revocation shall be in writing and delivered in a manner specified in G.S. 48-3-706(a) for revocation of relinquishments. An agency, which after the exercise of due diligence cannot personally locate the parent entitled to this notice, may deposit a copy of the notice in the United States mail, return receipt requested, addressed to the address of the parent given in the relinquishment, and the date of receipt by the parent is deemed to be the date of delivery or last attempted delivery. If a parent does not revoke the relinquishment in the time and manner provided in this section, the relinquishment is deemed a general relinquishment to the agency, and the agency may place the child for adoption with a prospective adoptive parent selected by the agency.
N.C. Gen. Stat. § 48-3-704