反对前提的选项就是错误的？

zmt526358998

The average life expectancy for the United States population as a whole is 73.9 years, but children born in Hawaii will live an average of 77 years, and those born in Louisiana, 71.7 years. If a newlywed couple from Louisiana were to begin their family in Hawaii, therefore, [ their children would be expected to live longer than would be the case if the family remained in Louisiana. ]
　　Which of the following, if true, would most seriously weaken the conclusion drawn in the passage?
　　A. Insurance company statisticians do not believe that moving to Hawaii will significantly lengthen the average Louisiana’s life.
　　B. The governor of Louisiana has falsely alleged that statistics for his state are inaccurate.
　　C. The longevity ascribed to Hawaii’s current population is attributable mostly to genetically determined factors.
　　D. Thirty percent of all Louisiana’s can expect to live longer than 77 years.
　　E. Most of the Hawaiian Islands have levels of air pollution well below the national average for the United States.


这题的答案是C，但是我不明白为什么B是错的。解释里说B攻击了premise所以是错的，但是我觉得虽然B挑战了题干的premise，但是如果B成立的话，确实weaken了conclusion啊，求解释~~~