The 'Dual Government' (diarchy) in Bengal, under which the Company had the revenue powers while the Nawab handled administration, was the brainchild of:

The "Dual Government" (diarchy) in Bengal was the brainchild of Robert Clive, who introduced it after the Company received the Diwani of Bengal, Bihar and Orissa.

About the Dual Government:

• The Company obtained the Diwani, the right to collect revenue, from the Mughal emperor Shah Alam II, under the Treaty of Allahabad.
• The Nawab of Bengal retained the Nizamat, that is, the responsibility for police, justice and general administration.
• However, the Nawab was dependent on the Company for money and military support, so he had responsibility without power.
• The Company had power without responsibility.
• The Company appointed two Indian deputy diwans to collect revenue on its behalf: Muhammad Reza Khan for Bengal and Raja Shitab Rai for Bihar.

Results:

• The system led to misrule, corruption and oppression.
• The Company's servants and their Indian agents extracted as much revenue as possible.
• Agriculture, trade and crafts suffered.
• The great Bengal famine occurred during this period.
• The system was later abolished, and the Company took direct charge of administration.

About Robert Clive:

• He was born in 1725 in England, and came to Madras as a clerk of the Company.
• He distinguished himself in the Carnatic wars, especially by the capture and defence of Arcot (1751).
• He led the Company's forces to victory at the Battle of Plassey (1757), and placed Mir Jafar on the throne of Bengal.
• He was Governor of Bengal twice (1757-1760, and again in the 1760s).
• In his second term, he tried to reform the Company's administration, banned private trade by Company servants and the receiving of presents, and dealt with the "White Mutiny" of officers.
• In England, he was investigated by Parliament for corruption, though he was not punished.
• He died in 1774.

Why not the other options?

• ✗Warren Hastings, Cornwallis and Wellesley came later.