在下列何种情况下，行政机关及其执法人员可以当场收缴罚款( )

A．给予二十元以下的罚款的

B．不当场收缴事后难以执行的

C．在边远、水上、交通不便地区，当事人向指定的银行缴纳罚款确有困难，经当事人提出的

D．对公民处以五十元以下、对法人或者其他组织处以一千元以下罚款的

— Could you tell us ______?

— About three weeks. [ ]

A. how often are we going to be away

B. how often we are going to be away

C. how long are we going to be away

D. how long we are going to be away