The correct answer is option 3, Ala-ud-din Khilji. He introduced the Market Regulation system during his reign.
Option 1, Muhammad-Bin-Tughlaq, is incorrect, as he is known for his unsuccessful attempt to introduce a token currency and shifting the capital city.
Option 2, Iltutmish, is also incorrect. While he made significant contributions to the Delhi Sultanate, he is not associated with the introduction of the Market Regulation system.
Option 4, Ghias-ud-din, is incorrect as well. He was the first ruler of the Mamluk dynasty but is not credited with introducing the Market Regulation system.
Therefore, the correct answer remains option 3, Ala-ud-din Khilji, as he is the ruler known for implementing the Market Regulation system.