Study the following information carefully and answer the question below.
(i) ′P×Q′ means `P is the brother of Q'.
(ii) 'P−Q' means 'P is the mother of Q'.
(iii) ′P+Q′ means 'P is the father of Q'.
(iv) ‘P÷Q′ means 'P is the sister of Q'.
Which of the following means 'B is the grandfather of F'?