I think it was the populations and wealth of people.
D. The reason for the fall of the Maya civilization is still unknown. There are many different theories attempting to explain the cause of the Classic Maya collapse and the abandonment of Maya cities in the southern Maya lowlands of Mesoamerica between the 8th and 9th centuries: climate change, drought, deforestation, etc. but although the drought is the leading theory at the moment the truth is yet unknown.
D. Europeans began questioning their faith in the Catholic Church.
