Study the following information carefully to answer the following questions.
(i) ′P×Q′ means P is the wife of Q.
(ii) ′P÷Q′ means P is the father of Q.
(iii) ′P+Q′ means P is the son of Q.
(iv) ′P−Q′ means P is the sister of Q.
Which of the following represents, 'S is the mother of T'?