问题:[单项选择题]
[单项选择题] When the dispute over duty payment arises between the duty payer and the Customs, the duty payer should first pay the duty and then, within ______ of the issuance of the duty memo, apply to the Customs in writing for a reconsideration of the case.
A.10days
B.20days
C.30days
D.oneyear