He got his first book published.It turned out to be a bestseller.

问题描述:

He got his first book published.It turned out to be a bestseller.
--- He got his first book published.It turnedout to be a bestseller.
--- When was _____?
--- _____ was in 2000 when he was still in college.
A.that; This B.this;It C.it; This D.that; It
选哪个,请详解原因,

选D
When was _____?中,用that指代那件事,疑问句中不用this
_____ was in 2000 when he was still in college 中it指代那件事,when后面是时间状语从句