By contract dated January 5, Rebecca agreed to sell to Nancy, and Nancy agreed to buy from Rebecca, a certain parcel of land then zoned commercial. The specific intent of Nancy, which was known to Rebecca, was to erect a manufacturing plant on the land; and the contract stated that the agreement was conditioned upon Nancy’s ability to construct such a plant upon the land. The closing date for the transaction was set for April 1. On February 15, the city council rezoned the land from commercial to residential, which precluded the erection of the plant. As the closing date drew near, Nancy made it known to Rebecca that she did not intend to go through with the purchase because the land could no longer be used as intended. On April 1, Rebecca tendered the deed to Nancy, who refused to pay Rebecca the agreed purchase price. Rebecca brought an action against Nancy for breach of their contract. Can Rebecca enforce the contract?