The British defeated the Chinese and forced them to accept a new trade agreement in the A.
Guangzhou War

B.
Taiping Rebellion

C.
Victorian War

D.
Opium War

Not just any war but

The Second Opium War

the picture is not clear

explanation:

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.