记录是为完成的活动或已达到的结果提供客观证据的文件，它是重要的信息资料，为证实可追溯性以及采取预防措施和纠正措施提供依据。 ( )

David’s effort was ______, because he won the first prize in the English speech contest, _____ made his classmates surprised.                                          

A．paid off; which

B．paid back; it

C．paid for; that

D．paid up; he