A client who is a gravida 1 para 0 has been admitted to the perinatal admission unit and is in early labor. The client’s cervical examination would reveal which of the following

A. 2 cm dilated; 100% effaced at 0 station.
B. 4 to 5 cm dilated; 80% effaced at -1 station.
C. 2 cm dilated; 50% effaced at +1 station.
D. 3 cm dilated; 50% effaced at 0 station.

应用戴维南定理求解图示电路中的电流I。