Answer:
The Incas used locally available material to sustain the empire.
Step-by-step explanation:
The Inca people were dependent locally available food sources in the form of edible roots, potatoes, maize, guinea pigs, llamas, dried fish, etc. They have sought methods to transform the barren land into more fertile and ideal for cultivation in South America. Where required, llama and alpaca fertilizer were used as an alternative fuel. The Inca Empire had huge amounts of bronze, gold, and silver and much of it was used for ritual purposes. They used stone and wood for construction purposes.