Rotation

This was the Question - The square is rotated one complete turn about the point O.
Which of the following shows the new position of the square?

This was the easy Rotation I did because all you did was a full turn, you just had to leave it there because it was a full turn 180 degrees                   

This is my answer and it was wrong

The Question - Rectangle A′B′C′D′ is the image of rectangle ABCD after which of the following rotations?

This one was hard and confusing because I didn't know what to do .