I had scarely left the house ( ) it began to rain.

I had scarely left the house ( ) it began to rain.
A、than
B、when
C、that
D、then
【正确答案】：B
【题目解析】：考核关联词组搭配 scarely…when… 一…就… ，句子含义是我一离开家，天就开始下雨了。