问题如下：
Analyst McHale is currently working on the stress tests being carried out by his client company. Stress testing considers multiple risk factors and designs multiple extreme scenarios that produce a synergistic effect of complex outcomes. The client company is asking McHale to participate in the improvement of this stress test design work. Which of the following options is McHale's biggest challenge in analyzing and improving this stress test?
选项：
A.Diversity.
B.Convenience and efficiency.
C.Rationality and possibility.
D.Usefulness.
解释：
C is correct.
考点：Stress test
解析：情景分析必须是基于极端条件下的，但这些极端条件，也必须具有coherent的特征，也就是这些场景必须是合理的、符合逻辑的，并且真的可能发生的。 这是设计压力测试时比较大的一个困难。因此选C。
这个知识点是在stress test的讲义的哪部分？
