Why Was the Discovery of Mercury in Peru Critical to the Colonial

Why was the discovery of mercury in Peru critical to the colonial economy?

A) Mercury was even more valuable than silver as an export commodity.
B) Mercury was a critical food component for the growing livestock inventories of New World ranches.
C) Mercury was indispensable to the extraction of silver from ore-bearing rock.
D) Mercury became a medium of exchange in place of money in the American economy.