谁解释这道题目

The "sucide wave" that followed the United States stock market crash of October 1929is more legend than fact.

Crareful examination of the monthly figures on the causes of death in 1929 shows that the nu7mber of suicides in October and in November was comparatively low.In only 3 other months were the monthly figures lower.During the summer months,when the stock market was flourshing,the number of suicides was substantially higher.

Which one ,if true would best challenge the conclusion of the passage?

C.The suicide rate in October and November of 1929 was considerably higher than the average for these months during several preceding and following years.为什么选C啊？我题目觉得看不懂，老师就说数字要同期对比，我还是不明白！

原文說十月份自殺人數比其他月份少，所以所謂的股市崩盤被誇大了

weaken就從自殺率的角度反駁。

说白了就是正常来讲在10月、11月自杀的人不多，但由于10月份股市崩盘，导致这两月自杀的人有所上升。

而夏天不管跟股市有没有关，自杀的人本来就很多。