According to paragraph 4, all of the following are signs of the great age of the Panaramitee engravings EXCEPT: A. The engravings consisted of simple animal drawings. B. The engravings were covered with a layer of a substance known as "desert varnish". C. Local Aborigines who were asked knew nothing about the origin of the engravings. D. Geologic changes had occurred after the engravings were made.