Who among the following Mughal Emperors, granted permission to trade of tax in the territories

Q. Who among the following Mughal Emperors, granted permission to trade of tax in the territories of Bengal. Hyderabad and Gujarat to the British?
(a) Aurangzeb
(b) Farrukh-siyar
(c) Bahadur Shah
(d) Muhammad Shah
Ans: (b) Farrukh-siyar