[b]A 27-year-old primigravid woman at 12 weeks' gestation comes to the emergency department 2 hours after the sudden onset of bright red vaginal bleeding. She has not had abdominal cramping. Pelvic examination shows a small amount of brownish blood in the posterior fornix of the vagina. The cervix is closed. The uterus is palpable 3 cm above the pelvic brim. Fetal heart tones are easily audible at 167/min by Doppler. Which of the following is the most likely diagnosis? [/b]

A ) Abruptio placentae

B ) Ectopic pregnancy

C ) Incomplete abortion

D ) Placenta previa

E ) Threatened abortion

F ) Normal pregnancy