问题详情

Customerstradingabroadinforeigncurrenciesmayprotectagainsttheexchangeriskbyarranging______.
A．acontractofinternationalsaleofgoods
B．acontractofmarineinsurance
C．aforwardcontracttofixtheexchangerateinadvance
D．contractforthedeliveryofgoodsbyinstallments

请帮忙给出正确答案和分析，谢谢！