As the busiest woman there, she made ____________ her duty to lo

As the busiest woman there, she made ____________ her duty to look after all the other people's affairs in that town.
A、this
B、that
C、one
D、it
【正确答案】：D
【题目解析】：本题考查it作形式宾语，代替to look after all the other people’s affairs in that town，其他选项均不可以充当形式宾语。