The nurse is providing care for a client who underwent mitral valve replacement. The best example of a measurable client outcome goal is to

A. change his own dressing.
B. walk in the hallway.
C. walk from his room to the end of the hall and back before discharge.
D. eat a special diet.

从安全生产角度解释，危险源是指可能造成人员伤害、疾病、财产损失、作业环境破坏或其他损失的( )。

A．原因

B．环境

C．条件

D．根源或状态