, Karen offered to sell a set of legal encyclopedias to Tony for $300. Tony said that he would think about her offer and let her know his decision the next day. Jim, who had overheard the conversation between Karen and Tony, said to Karen, "I accept your offer" and gave her $300. Karen gave Jim the books. The next day, Tony who had no idea that Karen has already sold the books to Jim, told Karen that he accepted her offer. Has Karen breached a valid contract with Tony? Explain?