9. Studies show that young people with higher-than-average blood pressure and their families have a history of high blood pressure are more likely than others to develop a severe form of the condition.
(A) and their families have a history of high blood pressure
(B) whose families have a history of high blood pressure
(C) and a history of high blood pressure runs in the family
(D) whose families have a history of high blood pressure running in them
(E) with a history of high blood pressure running in their family
[spoiler]
B[/spoiler]
(A) and their families have a history of high blood pressure
(B) whose families have a history of high blood pressure
(C) and a history of high blood pressure runs in the family
(D) whose families have a history of high blood pressure running in them
(E) with a history of high blood pressure running in their family
[spoiler]
B[/spoiler]
