一道高中英语语法题：He left so hurriedly to lock the door

一道高中英语语法题：He left so hurriedly to lock the door
He left so hurriedly ____to lock the door.
A.so as to forget B.to forget C.forget D.as forget
可是读上去句意不通啊 我选择是B
还有一道是：
He got up early ___the train.
A.so that he caught B.in order that C.he caught D.that he caught
答案显然是A 但是提示中说：so that he might catch 是目的状从 而so that he caught 是结果状从 为什麼