The correct option is C Bharhut sculptures
Bharhut sculptures used green schist as the medium means in this sculpture Green schist metamorphic rocks were used. In Mathura sculptures, red sandstone was used. In Gandhara Sculptures, bluish grey sandstone was used. The Mauryan, sculptures were rock-cut sculptures. In Maurya, sculptures buff colored fined grained hard sandstone and spotted red and white sandstone were used.