The correct answer is - B. medium.
China is a medium developed country, or as it is more often referred to a developing country. This may come as a surprise considering the China ii one of ths biggest producers of goods and services in the world, and it has the second biggest nominal GDP just after the USA.
Despite that, the GDP per capita in China is only 8,690 USD, putting it far behind the developed countries. Also, the country is not well known for respecting and promoting the human rights, instead it is very restrictive. The rural areas are in terrible conditions in general, and the pollution in the country is enormous, resulting in a very unhealthy living conditions.
All of these things put China in the frame of a developing country, though lot of people tend to disagree with that when its economic and political influence is taken in consideration.