[A]topay[B]paying[C]pay[D]tohavepaid

[A] to pay [B] paying [C] pay [D] to have paid

正确答案：C

此题属于语法题省略to的不定式作表语例如：AsIhadcreatedtheembarrassingsituationIknewthekindestthingIcoulddowastowalkaway

全句可译为：一旦生病无论是牙疼小孩生病还是心脏病所有忧心忡忡的人们所能做的就只是付清账单