Which of the following conditions will make a relation that is in first normal form to be in second normal form　　Ⅰ. every non-key attribute is functionally dependent on the full set of primary key attributes.　　Ⅱ. no non-key attributes exist in the relation.　　Ⅲ. the primary key consists of only one attribute.

A．Ⅰ only

B．Ⅰ and Ⅱ only

C．Ⅰ and Ⅲ only

D．any of them

腰椎间盘突出症下肢放射痛最常见于（）。

A.坐骨神经分布区

B.闭孔神经分布区

C.阴部神经分布区

D.股神经分布区

E.股外侧皮神经分布区