What became the main reason for Razia to rule the kingdom?

Directions: Read the passage and answer the following question.

Razia Sultan was the first woman who ruled medieval India, during the Muslim empire. Razia Sultan’s original name was Razia-al-Din. Her throne name was Jalalat-ud-Din Razia. She preferred to be called as Razia Sultan, as Sultana was feminist. Razia succeeded her father, Shams-ud-din-Iltutmish, to the sultanate of Delhi in 1236. While his sons were enjoying youth, Razia was actively participating in the administrative matters of the kingdom. Once, when Iltutmish was busy with the siege of Gwalior, he had entrusted the governance of Delhi to Razia. On his return, he was very much impressed by the way Razia had run the empire. At that very moment, he declared Razia as his heir. It was the will of the king that after his death, Razia, his daughter, should succeed the throne. But the Muslim people were not happy with this decision. When Iltutmish died, Rukn-ud-din Firuz, one of his sons, usurped the throne and ruled for about 7 months. Rukn-ud-din wasted all, after he got the control and the throne. Muslim nobility with reluctance agreed to allow Razia to rule the empire. She was an efficient Sultan, working for the betterment of the empire, but like her father, most of her time was spent in fighting rebellions. She had personally led the army to many places like Punjab and Multan. Her reign was just for three years, yet her bravery, struggle and her undaunted spirit has been preserved in the treasures of history.