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（B）

(E) with a history of high blood pressure running in their family

答案为什么是B? whose ---修饰pressure?

我觉得应在whose 前加个and. 请大家帮忙解释一下。

我选的是A。