Riddle

I turn once, what is out will not get in. I turn again, what is in will not get out. What am I?

Choose an answer

A.Door
B.Bolt
C.Handle
D.A key
Hint: It's a 2-word phrase with 4 letters, starting with "A".

Answer

A key

Why this is the answer

It is used to lock and unlock doors.

This riddle is filed under Expert Riddles for Adults and rated Hard.