this ArtiClE is mAinly ABout ______.
A．thE mAyAn CAlEnDAr AnD thE AnCiEnt mAyAn BuilDings
B．thE mAyAn inDiAns AnD thE mAyAn CAlEnDAr
C．thE intElligEnt mAyA AnD thEir mAny AChiEvEmEnts
D．thE AnCiEnt mAyAn CitiEs AnD tEmplEs