15.如【圖 15】所示之電路,若β=100,則 IB與 VE約為多少? (A) IB = 20μA,VE = 0V (B) IB = 20μA,VE = 2V (C)IB = 10μA,VE = −1V (D)IB = 10μA,VE = 1V