Software written test accumulation

1, a stack into the stack sequence for a B C D E is not possible output sequence for the reasons given:

1.EDCBA 2.DECBA 3.DCEAB 4.ABCDE

A: Select 3
Stack pay attention to advanced out, last in first out
Option 1 is ABCDE first into the stack, then out of the stack, exactly the EDCBA
Option 2 is ABCD first into the stack, then d out of the stack, E again into the stack, e out of the stack
Option 3 is wrong, not a first out stack
Option 4 is a into the stack, then a out stack, B again into the stack, b out of the stack. And so on
So choose 3.

Software written test accumulation