单项选择题

TEXT B
The promise of finding long term technological solutions to the problem of world food shortage seems difficult to fulfill. Many innovations that were once heavily supported and publicized, such as fish protein concentrate and protein from algae grown on petroleum substrates, have since fallen by the wayside. The proposals themselves were technically feasible but they proved to be economically unviable and to yield food products culturally unacceptable to their consumers.
One characteristic common to unsuccessful innovations has been that, even with extensive government support, they often have not been technologically adapted or culturally acceptable to the people for whom they had been developed. A successful new technology, therefore, must fit the entire social cultural system in which it is to find a place. Security of crop yield, practicality of storage, and costs are much more significant than had previously been realized by the advocates of new technologies.
The adoption of new food technologies depends on more than these technical and cultural considerations; economic factors and governmental policies also strongly influence the ultimate success of any innovation. Economists in the Anglo-American tradition have taken the lead in investigating the economies of technological innovation. Although they exaggerate in claiming that profitability-is the sky factor guiding technical change—they completely disregard the substantial effects of culture—they are correct in stressing the importance of profits. Most technological innovations in agriculture can be fully used only by large landowners and are only adopted if these profit-oriented business people believe that the innovation will increase their incomes. Thus, innovations that carry high rewards for big agribusiness (agricultural business) groups will be adopted even if they harm segments of the population and reduce the availability of food in a country. Further, should a new technology promise to alter substantially the profits and losses associated with any production system, those with economic power will strive to maintain and improve their own position. Since large segments of the populations of many developing countries are close to the subsistence margin and essentially powerless, they tend to be the losers in this system unless they are aided by a government policy that takes into account the needs of all sectors of the economy. Therefore, although technical advances in food production and processing will perhaps be needed to ensure food availability, meeting food needs will depend much more on equalizing economic power among the various segments of the population within the developing countries themselves.
The primary purpose of the passage is to discuss the ______.