19.Kofi Mensah makes an offer to sell his laptop to Nan Adjeley in exchange for GHC1.000.00. The offer is contained in a letter which is posted to Naa Adjeley on IN December, 2018 at 12 noon. Naa Adjeley receives and reads the letter on 2nd December, 2018 at 11am. She writes a letter in which she agrees to Kofi Mensah's offer. Naa Adjeley posts this letter to Kofi Mensah on 2nd December, 2018 at 4pm. Kofi Mensah, has a change of mind and calls Naa Adjeley on the phone to withdraw his offer on 2"d December, 2018 at 7pm. Naa Adjeley is not agreeable to Kofi Mensah's proposition. With the aid of decided cases, explain the legal effect of the parties' actions and determine whether or not there is a valid contract existing between the parties. Page 3 of 4