Which one among the following statements is not correct ?Gandhara School of Art owed its origin to the Indo-Greek rulers but the real patrons of the school were the Kushans, especially Kanishka Rich carving, elaborate ornamentations and complex symbolism were not the main features of the Candhara sculptureThe Graeco-Roman architectural impact modified the structure of Buddhist StupasThe artists of the Amravati School of Arts mainly used white marble