- A) Khilji dynasty - Ibrahim Lodi: Incorrect. Ibrahim Lodi was the last sultan of the Lodi dynasty. Alauddin Khilji was the most prominent ruler of the Khilji dynasty. - B) Delhi sultanate - Qutb-ud-din Aibak: Correct. Qutb-ud-din Aibak was the founder of the Mamluk dynasty (also known as the Slave dynasty), which was the first dynasty to rule the Delhi Sultanate, establishing its capital in Delhi. - C) Mughal empire - Akbar: Factually correct that Akbar was a Mughal emperor, but Babur was the founder of the Mughal Empire. - D) Tughluq dynasty - Firozshah Tughluq: Factually correct that Firoz Shah Tughlaq was a Tughluq sultan, but Ghiyas-ud-din Tughlaq was the founder of the Tughluq dynasty. Given the options and the phrasing "Which one...", option B provides the most direct and foundational link between the entity (Delhi Sultanate) and the ruler (its first Sultan), making it the intended correct answer over later rulers of other dynasties/empires.