The correct answer is (b), Qutubuddin Aibak.
Qutubuddin Aibak was a slave of a slave of Muhammad Ghori, the ruler of Ghor in Afghanistan. He was brought to India by Muhammad Ghori and became one of his most trusted generals. After Muhammad Ghori’s death in 1206, Qutubuddin Aibak became the first Sultan of Delhi.
Mohammad Ghori was a Muslim ruler from the Ghurid dynasty. He invaded India several times in the 12th century and conquered large parts of the country. He was killed in battle in 1206.
Balban was a Turkic slave who served under Qutubuddin Aibak and Iltutmish. He became the Sultan of Delhi in 1266 and ruled for 20 years. He is known for his military reforms and for his efforts to consolidate the Delhi Sultanate.
Iltutmish was a Turkic slave who served under Muhammad Ghori and Qutubuddin Aibak. He became the Sultan of Delhi in 1211 and ruled for 25 years. He is known for his military conquests and for his patronage of architecture.