Which of the following is not a stone sculpture of Gupta period?

The Sultanganj Buddha is a life-size metal sculpture cast in copper (using the lost-wax technique), not a stone sculpture, whereas the Sheshashayi Vishnu at Deogarh, the seated Buddha in Dharmachakra Pravartana Mudra at Sarnath, and the Varaha relief at Udayagiri caves are all Gupta-period stone sculptures.