Busy as they are，parents should________at least two hours every week to spend with their children.[ ]

A．set out  

B．set away

C．set aside 

D．set off

资金的时间价值又称货币的时间价值，是指现在的资金与将来同样多的资金相比，资金的价值是相同的，只是时间上的不一致。( )