At 38 weeks' gestation a client is admitted to the birthing unit in active labor, and an external fetal monitor is applied. Late fetal heart rate decelerations begin to appear when her cervix is dilated 6 cm and her contractions are occurring every 4 minutes and lasting 45 seconds. What does the nurse conclude is the cause of these late decelerations?a. 1Imminent vaginal birthb. 2Uteroplacental insufficiencyc. 3Pattern of nonprogressive labord. 4Reassuring response to contractions