In a traditionally drawn decision tree，a c
题型：单项选择题
问题：
In a traditionally drawn decision tree，a circle represents （）．
A．a chance to which no estimated monetary value can be assigned so that a likely pay-off can not be shown
B．a decision to which no estimated monetary value can be assigned so that a likely pay-off can not be shown
C．a chance to which an estimated monetary value may be assigned to calculate the most likely pay-off
D．a decision to which an estimated monetary value may be assigned to calculate the most likely pay-off