What topographical feature made it possible for the Olmec to become prosperous through trade? (1 point)%0D%0AResponses%0D%0A%0D%0Ariver system%0D%0Ariver system%0D%0A%0D%0Amountains%0D%0Amountains%0D%0A%0D%0Ajungle%0D%0Ajungle%0D%0A%0D%0Adesert%0D%0Adesert
