单选题 The primary purpose of the passage is to discuss the ______.

A、 means of assessing the extent of the world food shortage
B、 difficulties of applying technological solutions to the problem of food shortage
C、 costs of introducing a new food technology into a developing country
D、 nature of the new technological innovations in the area of food production

【正确答案】 B

【答案解析】推理题。通读全文，第一段为全文的中心，可以看出，全文都在探讨寻求解决粮食短缺问题的方案时所遇到的一系列困难。故选B项。