N.C. Gen. Stat. § 47G-4
A purchaser's right to exercise an option to purchase property under an option contract cannot be forfeited unless a breach has occurred in one or more of the purchaser's express obligations under the option contract and the option contract provides that as a result of such breach the seller is entitled to forfeit the contract. Notwithstanding any option contract or covered lease agreement provisions to the contrary, the purchaser's rights shall not be forfeited until the purchaser has been notified of the intent to forfeit in accordance with G.S. 47G-5 and been given a right to cure the default and has failed to do so within the time period allowed. The option purchaser is entitled to the right to cure a default once in every 12-month period during the period of the covered lease agreement.
N.C. Gen. Stat. § 47G-4