Given below are the four sentences in jumbled order. Pick the option that gives their correct order.

P. When she was told that she was expected to walk on the pavement she said that since she is free she has the liberty to walk where she liked.

Q. But if she walked in the middle of the road cars and vehicles could move on the pavement. This would result in chaos. 

R. Once an old lady was walking with a basket in hand in the middle of the street in Petrograd. 

S. It caused great confusion for the traffic.