Direction: The following question, consists of an incomplete sentence or a sentence which is split into four parts. All four parts are jumbled up and are named as P, Q, R and S. These four parts are not given in their proper order. Arrange the jumbled parts of the sentence and find out which of the four combinations from the given options will correctly complete the sentence.

without warning (P) slammed the brakes on (Q) I was driving in rush hour (R) when the driver in front of me (S)