（2010）根据《城市房地产管理法》，以出让方式取得土地使用权属于房屋建设工程的，按照土地使用权出让合同约定进行投资开发，其完成的开发投资达不到项目开发投资总额的（）以上的，不得转让。

A.15％

B.20％

C.25％

D.30％

Axel, a German furniture manufacturer, ordered 2,000 metres (m) of a particularly high quality coloured cloth from Beni, an Italian cloth manufacturer. 1,000 m of the cloth was to be red and the other 1,000 m green. When the cloth was delivered Axel found that the green cloth had been replaced by blue cloth.In spite of the change in the colour Axel used all the cloth without informing Beni and managed to sell all the furniture covered with it at its usual price. However he refused to pay Beni the full contractual price for the blue cloth as it was not what he had ordered.Required:Assuming that the UN Convention on Contracts for the International Sale of Goods applies, explain the rights and liabilities of the parties involved. (10 marks)