It's strange that he ( ) without saying goodbye to us.A.went outB.should go outC.had gone outD.should have gone out为什么选B?

It's strange that he ( ) without saying goodbye to us.A.went outB.should go outC.had gone outD.should have gone out为什么选B?
It's strange that he ( ) without saying goodbye to us.
A.went out
B.should go out
C.had gone out
D.should have gone out
为什么选B?

It's strange that he ( ) without saying goodbye to us.A.went outB.should go outC.had gone outD.should have gone out为什么选B?
It is strange(naturalsuggested,necessary,requested,ordered,proposed,important,surprising,strange,funny)+that+主语+shoud(可以省略）＋动词原形
这是虚拟语气在主语从句中的用法