请问这个句子为什么E答案不对

语法题,替换有底线的部分,我认为E不是很平行的并列结构吗?为什么答案是D?不理解

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.

(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