请教个语法题~急

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.

1. that they have twice the likelihood to get osteoarthritis of the knee as do White women
2. that they are twice as likely as White women to get osteoarthritis of the knee
3. that their likelihood of getting osteoarthritis of the knee is twice as much as White women
4. of being twice as likely as White women to get osteoarthritis of the knee
5. of having twice the likelihood of getting osteoarthritis of the knee as White women

答案是B，请问C为什么不对？

B项比较的双方是they（women of color)和White women ，可比

C项比较的是their likelihood 和White women ，所以错