Final answer:
William Pitt was the figure under whose strategic leadership the British forces were able to capture Fort Duquesne during the French and Indian War.
Step-by-step explanation:
The capture of Fort Duquesne during the French and Indian War was a significant event that took place after a series of engagements involving British and French forces, including those led by George Washington. However, it was not George Washington, Louis-Joseph de Montcalm, or Robert Rogers who captured Fort Duquesne.
The correct answer to the question is d. William Pitt. It was under the strategic leadership of British Secretary of State William Pitt that the British forces eventually were able to capture Fort Duquesne. Pitt reinvigorated the British military efforts by providing funds and resources, leading to significant victories including the takeover of Fort Duquesne, which was strategically important in controlling the Ohio River Valley.