单项选择题对债券现金流的贴现的函数以下哪种写法是正确的?()
A.cfs < -100*(rep(couponRate/frequency,n)+c(rep(0,n -1),1))
B.cfs < -100*(rep(couponRate/frequency,n-1)+c(rep(0,n -1),1))
C.cfs < -100*(rep(couponRate/frequency,n)+c(rep(0,n -1))
D.cfs < -100*(rep(couponRate/frequency,n)+c(rep(0,n ),1))