In the middle of the 18th century (c. 1750s), Bengal was the most prosperous province of the Mughal Empire and the primary base for the English East India Company's trade. The staple commodities exported from Bengal were:

• Cotton and Silk: Bengal was world-renowned for its high-quality textiles, including fine muslins and silk fabrics, which were the most sought-after Indian exports in European and Asian markets.
• Saltpetre: This was a strategic commodity used as a key ingredient in the manufacture of gunpowder. Bengal was the primary source of saltpetre for European powers during the frequent wars of the 18th century.
• Opium: Bengal was a major producer of opium, which the East India Company exported primarily to China and Southeast Asia. While the Company's formal monopoly was established in 1773, it was already a staple export item by the mid-18th century.

Note on other options: During this period, India was a 'sink' for precious metals; therefore, copper, silver, and gold (Option C) were typically imported into India as bullion to pay for Indian goods, rather than being exported.