A Woman Is 7 Cm Dilated,and Her Contractions Are 3

A woman is 7 cm dilated,and her contractions are 3 minutes apart.When she begins cursing at her birthing coach and the nurse,the nurse assesses the most likely explanation for the woman's change in behavior is that:

A) labor has progressed to the transition phase.
B) she lacked adequate preparation for the labor experience.
C) the woman would benefit from a different form of analgesia.
D) the contractions have increased from mild to moderate intensity.