On May 4, Stephanie sent a letter to Ian offering to sell her Transformers action figure to Erica for $75. The offer stated that it would expire on March 8. On June 17, Cleo sent another letter to Ian that stated that she was withdrawing the offer because she changed her mind. Erica received that letter on October 5.

Additionally on September 30, Ian sent a letter to Stephanie accepting the offer. Stephanie received that letter of acceptance on October 2. Cleo refused to sell the action figure to Ian, claiming that no contract had been formed because she had withdrawn her offer. Ian brought a lawsuit to enforce the contract against Stephanie.Is there any evidence of mutual assent in this case? How is this exercised? Please elaborate on answer..