is this the museum ( ) they visited last month?

问题描述:

is this the museum ( ) they visited last month?
A.the one B.when C.where.D.which

D,还原成陈述句看,this is the museum (that) which they visited last month
有一个类似的,this museum is what they visited last month(非定语从句,好像是主语从句)