Which of the Following Contributed to the End of Brazil's

Multiple Choice

Which of the following contributed to the end of Brazil's rubber boom?

A) Increased production outside of Brazil led to more competition and lowered prices.
B) Rain forest land was damaged by cattle grazing and wildfires.
C) Hostile Amerindians attacked rubber plantations and convoys.
D) The expense of building the Manaus Opera House bankrupted many elites.