What is the mystery of Tiahuanaco?

(1 point)
Responses

No one knows where it is.
No one knows where it is.

No one knows why people lived there.
No one knows why people lived there.

No one can decipher their writings.
No one can decipher their writings.

No one knows why the people there disappeared.
No one knows why the people there disappeared.

No one knows how they built their intricate structures.