UPSC 2013 CDS 2 English Paper

‘P’ will be the first part of the given sequence as it contains thesubject, that is, ‘This is the book’. ‘R’ will follow next as ‘that’ is used to refer to an object. ‘S’ and ‘Q’ will follow logically as they complete the meaning of the sentence and refer back to the subject. Hence, PRSQ is the correct sequence. Thus, option(a) is correct.