Answer: Merchants from different places exchange one type of coin to another.
Explanation: Moneychangers were in (virtually) every city's harbor. Traders from foreigns country came to moneychangers to change their money to the local currency (AKA local coin) so that the traders could do buisness in that country
Smoking became very popular.
Changed diet kept people from starvation.
Corn fed livestock grew in places where other plants couldn't grow in
Considerable investments in agriculture have enabled China's farmers to produce high volumes of staple crops, allowing the country to achieve a roughly one-to-one ratio of production and consumption of grains.
Well to start of with u can cross out a and c so now your left with b and c
So the answer is (D)
