In ancient times the Chinese people carved and painted many symbols on pottery. Which of the following are true about these symbols?
选项：

A:They are geometric and image-based symbols.;
B:They were discovered later than Jiaguwen.;
C:The image symbols carved and painted during the Dawenkou Culture should be described as the original image characters.;
D:Han characters have been developed out of the images of clan totems or clan emblems.