求解一道语法

       7. The most common reasons for an employee's unwillingness to accept a transfer are that mortgage rates are high, housing in the new location costs more, and the difficulty of selling the old home.

    (A) that mortgage rates are high, housing in the new location costs more, and the difficulty of selling the old home.

    (B) that mortgage rates are high, housing in the new location costs more, and that it is difficult to sell the old home

    (C) high mortgage rates, the greater cost of housing in the new location, and that the old home is difficult to sell

    (D) high mortgage rates, the greater cost of housing in the new location, and it is difficult to sell the old home

    (E) high mortgage rates, the greater cost of housing in the new location, and the difficulty of selling the old home

没有答案，个人觉得选E，不知道对不对。还有就是请问这题的并列结构是不是mortgage,housing和difficulty这三个词?         希望牛人给予解答，谢谢。

我支持E，排除最方便

并列的我觉得是这三个，虽然不是一个类型的名词，但是既然问的是reason,只要词性一样就成