‘Q’ will be the first part of the given sequence as it is in continuation with the previous statement and describes the subject mentioned in detail. ‘S’ will follow next as it refers back to theprevious statement which is clear from the words, ‘their aunt’. ‘P’ will come next as it is in continuation with the previous statement which is clearly indicated from the words, ‘The children were pestering their aunt’.‘R’ will follow logically as it begins with the word, ‘Luckily’ and completes the plot. Hence, QSPR is the correct sequence. Thus, option (b) is correct.