John Marshall, the acclaimed British archaeologist, could study the Sanchi stupa when it was under:

The rulers of Bhopal

The correct answer is Option (2) → The rulers of Bhopal

The rulers of Bhopal, Shahjehan Begum and her successor Sultan Jehan Begum, provided money for the preservation of the ancient site. No wonder then that John Marshall dedicated his important volumes on Sanchi to Sultan Jehan. She funded the museum that was built there as well as the guesthouse where he lived and wrote the volumes. She also funded the publication of the volumes. So if the stupa complex has survived, it is in no small measure due to wise decisions, and to good luck in escaping the eyes of railway contractors, builders, and those looking for finds to carry away to the museums of Europe.