The grant of Diwani of Bengal, Bihar and Odisha is associated with:

The correct choice is: “Shah Alam II”

After the Battle of Buxar (1764), the Treaty of Allahabad (August 1765) was signed between Robert Clive and the Mughal Emperor Shah Alam II. By it Shah Alam II granted the East India Company the Diwani, the right to collect revenue, of Bengal, Bihar and Orissa, in return for an annual tribute of ₹ 26 lakh.

Nawab Shuja-ud-Daula of Awadh signed a separate treaty at Allahabad and paid war damages, but he could not grant the Diwani; only the emperor could. Asaf-ud-Daula was his successor, and Shah Alam I (Bahadur Shah I) ruled in 1707–1712.