The correct answer is option4) i.e. RQPS Explanation: R starts with 'there was'. So it is an introductory part of the sentence. The difference is followed by'between'. Q starts with between. So it is the second part of the sentence. 'P' and 'S' are the same types of parts of the sentence. The only difference is that 'P'carries a noun( a bridge) and 'S' carries a pronoun 'one' So' P' and 'S' will be the third and fourth part of the sentence respectively. Hence we can say that the sentence will start with 'R' and will be followed by'Q.' P' will be the next part and be followed by 'S'. 'Important Point: Noun comes first in the sentence and is followed by a pronoun. Thus the correct order is RQPS Correct Sentence: "There was a marked difference of quality between the two persons who haunted the bridge of brick and who haunted the far one of stone".