‘Q’ will be the first part of the given sequence as it is incontinuation with the previous statement which is clearly indicatedfrom the words, ‘All of a sudden’. ‘S’ will follow next as it tells about the reaction of the subject in the previous statement. ‘P’ will comenext as it refers back to the previous statement and takes the story further which is clear from the words, ‘I thought’. ‘R’ will follow logically as it takes the story further and throws light on the actions of the speaker. Hence, QSPR is the correct sequence. Thus, option (b) is correct.