Az is an international metals broker with clients all round the worlD、In January he entered into three contracts:(a) the first, to supplyBrad with 1,000 tonnes of aluminium;(b) the second, to supplyChad with 1,000 tonnes of copper;(c) the third, to supplyDan with 1,000 tonnes of tin.AlthoughAz had immediate access to the metals from his extensive reserves, delivery on all three contracts was to take place on 1 May. However, as he wanted to reduce his exposure to such a large inventory of metalsAz decided to supply the metals to the three other parties earlier than the contract date; 1 March rather than 1 May.BecauseAz’s inventory of aluminium was only 1,000 tonnes that is what he sent toBraD、However, as he had larger inventory of copper and tin, he decided to send an additional 500 tonnes to bothChad andDan, over and above their agreed amounts.At the end of February, afterAz had despatched the metals, the international metals market suffered a severe upheaval, with the price of copper falling by 50% and the price of tin increasing by the same percentage. The price of aluminium remained constant.Required:AdviseBrad,Chad andDan as to their rights under the UNConvention for the International Sale of Goods. (10 marks)