A 20-year-old G1 at 38 weeks gestation presents with regular painful contractions every 3 to 4 minutes lasting 60 seconds. On pelvic examination, she is 3 cm dilated and 90% effaced; an amniotomy is performed and clear fluid is noted. The patient receives epidural analgesia for pain management. The fetal heart rate tracing is reactive. One hour later on repeat examination, her cervix is 5 cm dilated and 100% effaced. Which of the following is the best next step in her management?
a. Begin pushing
b. Initiate Pitocin augmentation for protracted labor
c. No intervention; labor is progressing normally
d. Perform cesarean delivery for inadequate cervical effacement
e. Stop epidural infusion to enhance contractions and cervical change