下述内容有哪一项不是心身疾病

A．偏头痛

B．支气管哮喘

C．过敏性结肠炎

D．神经症

E．经前期紧张症

Schools in the east tend to be better equipped, ____ those in the west are relatively poor.[ ]

A. As              

B. While            

C. When            

D. But