Study the following information carefully and answer the questions given below.
(i) P×Q means 'P is the mother of Q'.
(ii) P+Q means 'P is the sister of Q'.
(iii) P÷Q means 'P is the father of Q'.
(iv) P−Q means 'P is the brother of Q'.
Which of the following means 'M is the niece of R'?