What was the result of using die stamps and electrum in the ancient world?

They use it for Trades, send messages or make contractual agreement.

Explanation:

Plectrum is a naturally occurred  alloy of silver or gold. Civilizations in the past use this to make coin. After the ancient world discovered coin, they started to use it as a medium of exchange in order to measure the value of resources. (the more valuable the resource, the higher amount of coins they require to get it). This lead to the development of trades.

As for die stamps, they use it in order to formalized their writings. Official government often have unique type of stamps that can be used as a proof of authenticity of a certain document.

d is the correct answer.

b is incorrect because it makes food by itself

c is incorrect because us humans don't know how to produce their own food using the sun like plants.

a is incorrect because consumers can depend on carnivores for eating food for consumers to eat the dead organism. same thing with omnivores.

they could have terrible tropical storms which will destroy the crops in the colonies