(单选题)

The foremost reason why the egg-based method is defective lies in _____.

A.the complex process of vaccine production

B.its potential threat to human being

C.the low survival rate for new flu vaccines

D.its contribution to the flu vaccine shortage

参考答案：C

参考解析：

细节理解题。根据第三段“One is the long lead time needed to order the eggs...the demand for flu vaccine.”可知尽管鸡蛋是可靠的，它们也有严重的缺陷。首先是订购鸡蛋所需要的前置时间很长。这意味着在突发的疫苗短缺状况下很难立刻生产更多的疫苗。要满足对流感疫苗的需求需要生产几百万的剂量，而使用鸡蛋也许跟不上这个速度。故选C。

知识点：阅读理解四选一英语专业基础知识阅读理解教师招聘-小学英语