18. 如圖(七)所示之BJT電路,VBB = 3 V,VCC = 12 V,RB = 115 kΩ,RC = 2.7 kΩ,β = 200,則IC =?(A) 3.2mA (B) 4.0mA(C) 5.0mA(D) 8.2mA