下列各项中，属于非现金支付工具的有（）

A．Proof of a  clear link  between job satisfaction, worker motivation  and  business success
B．Concern for productivity and  efficiency
C．Awareness of the  many different variables that influence and  constrain  a  manager's behaviour
D．Awareness of the  importance of group dynamics and  worker attitudes as an  influence on productivity

A．
B．
C．
D．