问题详情

Passage Three：Questions 31 to 35 are based on the following passage.As supplier of most of the food we eat and of raw materials for many industrial processes, agriculture is clearly an important area of the economy. But the industrial performance of agriculture is even more important than this. For in nations where the productivity of farmers is low, most of the working population is needed to raise food and few people are available for production of investment goods or for other activities required for economic growth. Indeed, one of the factors related most closely to the per capital income (人均收入) of a nation is the fraction of its population engaged in farming. In the poorest nations of the world more than half of the population lives on farms. This compares sharply with less than 10 per cent in Western Europe and less than 4 per cent in the United States.
In short, the course of economic development in general depends in a fundamental way on the performance of farmers. This performance in turn, depends on how agriculture is organized and on the economic environment, or market structure, within which it function. In the following pages the performance of American agriculture is examined. It is appropriate to begin with a conversation of its market structure.
第31题：This passage is most probably ________.
A) a news item
B) part of an introduction of a book
C) part of a lecture
D) an advertisement请帮忙给出正确答案和分析，谢谢！