(1) Nelson placed the following advertisement on the notice board at his local supermarket. \"For Sale. iPhone8. Black. 64 GB - comes complete with earphones, USB cable and power adapter. $650. Must sell before Friday 31St August. Phone Nelson 021 01201 1110.\" On Wednesday Ralph saw the advertisement and immediately phoned Nelson. Unfortunately Nelson was not able to take the call and it was diverted to his message service. Ralph left the following message, \"I'm calling about the phone in the \"For Sale\" notice at the supermarket. I accept. I'll pay the $650 - cash immediately. Call me back and we can arrange how I can collect the phone.\" Nelson met Lisa on Saturday 1st September who said she would pay $700 for the phone. Nelson said he wanted time to think about it. Before he replied to Lisa he checked his messages and heard the call from Ralph. Analyse this scenario and advise Nelson of his legal position