The correct answer is declaring war
I cant tell u on the site i posted the answer on answers.com
Answer:i think its the last one
Explanation:For their city to endure, the Inca had to find a way to keep it from sliding down the mountain. Perhaps the most visually striking features of the drainage system are the agricultural terraces. Machu Picchu includes 4.9 ha of agricultural terraces, which are held in place by stone retaining walls.
