In Rubaria, excellent health care is available to virtually the entire population, whereas very few people in Terland receive adequate medical care.  Yet, although the death rate for most diseases is higher in Terland than in Rubaria, the percentage of the male population that dies from prostate cancer is significantly higher in Rubaria than in Terland.

Which of the following, if true, most helps to explain the disparity between the prostate cancer death rate in Rubaria and Terland?

A.    Effective treatment of prostate cancer in its early stages generally requires medical techniques available in Rubaria but not in Terland.

B.    Most men who have prostate cancer are older than the average life expectancy for male inhabitants of Terland.

C.    Being in poor general health does not increase one’s risk of developing prostate cancer.

4. It is possible to decrease one’s risk of getting prostate cancer by eating certain kinds of foods, and such foods are more readily available in Rubaria than in Terland.
5. Among men in Rubaria, the death rate from prostate cancer is significantly higher for those who do not take full advantage of Rubaria’s health care system than for those who do.

答案选b, 没明白b为什么能解释原文中的不一致

请教明白之人, 多谢!