Are similar to the gulkis of the Middle Ages,

1.Banks
2.Labor unions
3.Shopping malls

when a country suffers, for example, a drought period, the market product is affected for a low offer, in this case, potatoes; the government has to tax to the households, which have to give more money for the potatoes which they consume, that situation make them consume substitute goods even through loans, it could increase the financial market movement and the inflationary phenomena, the business has to increase salaries in order to the employees could buy a more expensive food (potatoes) and in order to inflation tha business had to buy expensive supplies in the factor market, while the rest of the world have to gain more money to consume the same amount of potatoes.

sadi to be the richest man ever with a net worth of 500b or half a trillion there is also a story i heard if you wanna know

d is definitely the answer