How did Sultan Qutb-ud-din Aibak die

(a)

He was treacherously stabbed to death by one of his ambitious nobles.

(b)

He was killed in a battle with Taj-u-din Yildiz, the ruler of Ghazni who entered into a contest with him over the capture of Punjab.

(c)

He sustained injuries while besieging the fortress of Kalinjar in Bundelkhand and succumbed to them later.

(d)

He died after a fall from his horse while playing Chaugan.