Option c is the correct answer. Muhammad Bin Tughluq, the ruler of the Delhi Sultanate, is considered the most learned ruler of the Delhi sultanate. He possessed a deep understanding of various disciplines such as astronomy, mathematics, medicine, and philosophy. His intellectual pursuits and interest in subjects beyond political matters set him apart. He was known for his proficiency in Persian and Urdu/Hindustani poetry, logic, Greek metaphysics, and science. His wide-ranging knowledge and contributions to various fields reflect his status as an erudite ruler of the Delhi Sultanate.