A. Jalal ud din
B. Ibn Al Haitham
C. None of these
D. Omar Khayyam
🧠 Explanation:
The Jalali calendar, a solar calendar, was developed by Omar Khayyam, a renowned Persian mathematician and astronomer, in the 11th century. Commissioned by Sultan Malik Shah I, it improved the accuracy of the Persian calendar by aligning it with the solar year through a precise leap year system. Implemented during the Seljuk Empire, the Jalali calendar influenced subsequent regional calendars. Khayyam’s astronomical expertise ensured its reliability, reflecting his significant contributions to science and governance. The calendar’s legacy underscores the integration of scientific innovation with administrative needs in medieval Islamic civilization.
