भारत में पूर्णतः इस्लामी निर्माण परंपरा के आधार पर (बिना किसी हिंदू प्रभाव के) निर्मित प्रथम मस्जिद कौन सी मानी जाती है?

Who constructed Sultangarhi in Delhi, regarded as the first Islamic mausoleum built in India?

Consider the following statements regarding the Tomb of Iltutmish (c. 1235): 1. It is the first tomb of a ruling Sultan built in India, attached to the Quwwat-ul-Islam Mosque complex. 2. Its chamber is square in plan with the earliest squinch arches in Indian architecture, though corbelled rather than true/radiating — true squinch arches appear only later at the Alai Darwaza (1311). 3. The interior walls are profusely decorated with Arabic inscriptions from the Quran and geometric/arabesque ornament executed by indigenous craftsmen. 4. It was originally covered by a true dome that has survived intact. Which of the above statements are correct?