Compare the emergence of advanced civilizations in Meso and South America with the four early river valley civilizations. By introducing Hinduism to the Indus River valley, the Aryans played a similar role to whom in the Mayan civilization? (10 point) 
 a. the Toltecs, who introduced Christianity 
 b the Dravidians, who introduced Buddhism
 c the Spanish conquistadors, who introduced Buddhism 
 d the Spanish conquistadors, who introduced Christianity