The correct option is A Robert Clive
The system of Dual Government was introduced in Bengal by Robert Clive of British East India Company. It lasted from 1765 to 1772. Under this system, the administration of Bengal was divided into Nizamat and Diwani. The Diwani was carried out by the company and the Nizamat by the Nizam. The system was abolished by Warren Hastings in 1772 and Bengal was brought under direct control of the British and the Nawabs remained as the mere pensioners of the East India Company.