‘P’ will be the first part of the given sequence as it contains thesubject, that is, ‘the dog’. ‘S’ will follow next as per the subject-verbagreement rule, that is, ‘wagged his tail’. ‘R’ will follow logically as it is the object of the sentence, that is, ‘before the master’. ‘Q’ will logically follow ‘R’ as it describes the actions in the previous part of the sentence. Hence, PSRQ is the correct sequence. Thus, option (b) is correct