Selco did not deliver the first 5,000 brake linings on May 31, or at any time thereafter; on June 10, Selco notified Byco that it would not perform the contractWhich of the following correctly states Byco's rights and obligations immediately after receipt of Selco's notice on May 10?
Byco had no cause of action for breach of contract, but could suspend its performance and demand assurances that Selco would perform. 
Byco had no cause of action for breach of contract, and was required to pay the installment of the purchase price due on May 15 to preserve its rights under the contract.
Byco could treat the notice as an anticipatory repudiation, and had a cause of action on May 10 for breach of the entire contract 
Byco could treat the notice as an anticipatory repudiation, and could sue to enjoin an actual breach by Selco on May 31. 