On May 1, Ohner telegraphed Byer, "Will sell you any or all of the lots in Grover subdivision at $5,000 each. Details will follow in letter." The letter contained all the necessary details concerning terms of payment, insurance, mortgages, etc., and provided, "This offer remains open until June 1." On May 2, after he had received the telegram but before he had received the letter, Byer telegraphed Ohner, "Accept your offer with respect to lot 101." Both parties knew that there were 50 lots in the Grove subdivision and that they were numbered 101 through 150."For this question only, assume that on May 6 Byer telegraphed Ohner, "Will take the rest of the lots," and that on May 8 Ohner discovered that he did not have good title to the remaining lots. Which of the following would provide the best legal support for Ohner's contention that he was not liable for breach of contract as to the remaining 49 lots?
Impossibility of performance. Unilateral mistake as to basic assumption. Termination of the offer by Byer's having first contracted to buy lot 101. Excuse by failure of an implied condition precedent.