One import and export company exported a batch of goods under CIF term. The seller delivered the goods on board the vessel on time and made out all necessary documents. But the vessel stranded  and  sank in a few hours after departure. The  next day , when the  seller asked for payment with all set of documents in conformity with the contract, the buyer refused to accept the documents and rejected payment because his goods have been lost. Question: Is it reasonable for the buyer to do so? Why? (Translate the case into Chinese and then answer the question) Helpful hint: The case is mainly about the CIF term.