The savior of the Delhi Sultanate refers to the ruler who successfully protected and strengthened the Delhi Sultanate during a period of instability or crisis. In this case, the correct answer provided is option 4, Ghias-ud-din Balban. Ghias-ud-din Balban was a powerful ruler who came to power after the reign of Razia Sultan. He played a crucial role in stabilizing the Delhi Sultanate and consolidating its power. Balban implemented strict measures to maintain law and order and effectively dealt with rebellions and invasions. He also strengthened the administrative system and improved the military capabilities of the Sultanate. Balban`s reign is considered to be a period of strong and effective governance, making him the savior of the Delhi Sultanate.