✔ 最佳答案
First, I need to know what does 3days means, from 15th to 17th? or 18th? If it is 18th, then then it is a breach of contract, Arthur is not allowed to make a contract without telling Morris before the deadline. If the deadline is 17th, then it is alright for Arthur to make another contract with Lawfan, and the contract between Arthur and Morris is expired, so he doesn't have to sell the bicycle to Morris.
I didn't see clearly what Lawfan has said 'I will need to pay 2 installments.[[[[["]]]]]]Arthur was upset about this and simply hung up.'
Anyway, if Arthur is upset about what Lawfan has said then has doesn't have to sell the bicycle to him, because he has not agreed to sell it to him yet, so he can make a NEW contract about selling the bicycle to Morris if he would like to.