Wellesley established the Fort William College at Calcutta because

Wellesley founded Fort William College in 1800 mainly to train young British covenanted servants of the East India Company before they took up posts in Bengal. They learned Bengali, Hindustani, Persian, Sanskrit and local law and custom, which made them usable in revenue and judicial work. That makes D the correct answer.

• A is wrong: the Court of Directors in London was actually unhappy with the cost and scale of the college. They later set up Haileybury College in England in 1806 to do this training at home.
• B is wrong: oriental scholarship was a by-product. It was not the stated reason, and the college's core purpose was administrative.
• C is wrong: William Carey and others were hired as teachers, but that was a consequence of the college, not its reason.

The core concept is the Company's shift from trading to governing, which needed trained officials who could work with Indian languages and people. This links to the Orientalist versus Anglicist debate and Macaulay's 1835 Minute, a useful Mains thread on colonial knowledge production. The college declined and closed in 1854.

Trap: aspirants pick B because the college is famous for Bengali and Sanskrit scholarship. Always ask what the founder's stated aim was, not what the college ended up producing.