How were agricultural abundance and the growth of cities connected​

So when people dont need to produce there own food they do other services and work. like making cloths and other things. but they needed to be within a close distance of whoever was making the food so they could trade there service. or product for the food. and there product for other products. so thats how cities came to be. and thats why populations are dense in area

in short TLDR : to trade stuff and work for the guy/girl growing the food

the answer for 3 is b and the answer for 4 is d

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.