A ____________D
l w l
l s _l_ N l
l l l
l E l
C____________B

from the original position given in the figure above , A and B moves one arm length clockwise and cross over to the diagonally opposite corners. C and D move one arm length anticlockwise and cross over the diagonally opposite corners. the original configuration A,D,B,C has change to

1. cbda
2. bdac
3. dacb4. bcad