Wei Wei, Ltd

Wei Wei, Ltd., a Chinese firm, delivers the first commercial unit of a two-unit shipment of headphones to Sonic Boom, a U.S.firm.Sonic accepts the goods, but later discovers that they are nonconforming.To revoke acceptance of the unit under the Convention on Contracts for the International Sale of Goods, Sonic

A) can sue immediately, claiming that Wei Wei fundamentally breached the contract.
B) must notify Wei Wei and return the goods before Sonic can sue.
C) must prove that the nonconformity of the first unit impaired the value of the whole lot.
D) must prove that Sonic assumed the nonconformity would be cured and it has not been cured.