正确答案：
B
解析：
主旨题。录音首句便指出malnutrition（营养不良）的问题，接着对该问题出现的原因、造成的危害及解决方法等进行了详细的分析。由此可推断，该段录音主要讲述如何应对营养不良问题。因此选项B的内容与录音主要意思相符。
【录音原文】
In most corners of the world malnutrition is plainly a matter of outright insufficiency of food for population—where the majority of the people do not obtain enough food calories to meet minimal needs for support of physical work and for maintenance of health. Elsewhere the problem may be not one of insufficient calories but of lack of specific nutrients essential for health.
In Latin America, as in other places, the dread protein deficiency disease kwashiorkor is taking its heavy toll on children’s lives. Strategic vitamins and minerals may be lacking due to traditional diets which are nutritionally imbalanced. Here people continue their eating pattern year after year without knowledge of what their dietary habits are doing to themselves and to future generation. With a basic knowledge of nutritional needs and deficiencies, efforts would be directed to finding food substitutes which could meet these needs. Mixtures of vegetable proteins, like soybeans and peanuts, could provide an abundance of cheap, useful protein where meats, eggs, and milk are not within economic reach of large groups in the population. Efforts could also be expanded on increasing the agricultural productivity in specific regions; where large areas are given over to relatively inefficient use as grazing land, the intensive production of vegetable protein crops could bring remedial nutrition to an undernourished population.
