A plan was made last year ______ several roads would be built in

A plan was made last year ______ several roads would be built in this part of the city.
A、as
B、where
C、which
D、that
【正确答案】：D
【题目解析】：译文：去年制定了一个计划，将要在这个城市的这个地区修建几条公路。此题考查同位语从句。