The Arthritis Research Institute of America advises women of color that they have twice the likelihood to get osteoarthritis of the knee as do White women.

that they have twice the likelihood to get osteoarthritis of the knee as do White women

that they are twice as likely as White women to get osteoarthritis of the knee

that their likelihood of getting osteoarthritis of the knee is twice as much as White women

of being twice as likely as White women to get osteoarthritis of the knee

E. of having twice the likelihood of getting osteoarthritis of the knee as White women

我也选了c，不过b的确有道理。

如果说b一定对，可以调c中错误。它的比较对象混了，their likelihood和white women比较了，白女人前省了that of。

还有动词优于动名次原则，to get 比of getting好。不知道对不对。

请nn指教！

C 的错误很明显，比较对象不对称。