we are going to spend the holiday in Guangzhou,（）live my grandparents

we are going to spend the holiday in Guangzhou,（）live my grandparents
A which B that C who D where
请问为什么用where,先行词是Guangzhou,从句倒装,陈述句应该是my grandparents live in guangzhou,这样看来空格里代表先行词在从句中做宾语,既然作宾语,为什么不适用which that 或者省略?还是说应该从live是否是及物动词的角度去考虑,如果是vt,空格中做宾语,如果是vi,空格中做状语
求高人指点