大全28套Section II-12 一个干扰项为什么不对，谢谢大家

The higher the average fat intake among the residents of a country, the higher the incidence of cancer in that country; the lower the average fat intake, the lower the incidence of cancer. So individuals who want to reduce their risk of cancer should reduce their fat intake.

Which one of the following, if true, most weaken the argument?

(A) The differences in average fat intake between countries are often due to the varying makeup of traditional diets.

(B) The countries with a high average fat intake tend to be among the wealthiest in the world.

(C) Cancer is a prominent cause of death in countries with a low average fat intake.

(D) The countries with high average fat intake are also the countries with highest levels of environmental pollution.（D）

(E) An individual resident of a country whose population has a high average fat intake may have a diet with a low fat intake.

为什么C不对哪？D要反对的话还得有个假设吧，就是Pollution和Cancer有关系，这样Pollution才能成为他因啊

C的话不是无因有果么？为什么不对呢