Which of the following is not a theory for the decline of the Mayan civilization?

a.

a natural disaster

c.

a lack of invention and adaptation

b.

the invasion by another group

d.

an internal revolt

I'd say the invasion by another group

The answer is for sure D, can't be lack of invention hell one of the first civilizations to have water moving up and down slopes, invasion of another group is what happened (Spanish) and an natural disaster was never talked about in historical context