Six identical balls are lined in a straight groove made on a horizontal frictionless surface as shown. Two similar balls each moving with a velocity v collide elastically with the row of 6 balls from left. What will happen

One ball from the right rolls out with a speed 2v and the remaining balls will remain at rest

Two balls from the right roll out with speed v each and the remaining balls will remain stationary

All the six balls in the row will roll out with speed v/6 each and the two colliding balls will come to rest

The colliding balls will come to rest and no ball rolls out from right