腹股沟管的下壁是

A．腹外斜肌腱膜纤维在耻骨结节上方形成三角形裂隙

B．腹外斜肌腱膜及腹内斜肌

C．腹内斜肌和腹横肌弓状下缘

D．腹横筋膜联合腱

E．腹股沟韧带

An asset is considered impaired if:（）

A. fixed assets are lower than current assets.  

B. assets are carried below their market values.  

C. assets are carried at more than the sum of their undiscounted expected cash flows.