Final answer:
In case preterm labor is unable to be arrested, the nurse should prepare the mother for emergency cesarean section, implement measures to support the premature infant's respiratory system, and administering oxytocin to strengthen contractions would not be appropriate.
Step-by-step explanation:
If preterm labor is unable to be arrested, there are several special actions that the nurse should take during the intrapartum period. One important action is to prepare the mother for emergency cesarean section (A). This may be necessary if the health of the mother or baby is at risk and vaginal delivery is not feasible. Another action is to implement measures to support the premature infant's respiratory system (C) since premature infants often have underdeveloped lungs and may require supplemental oxygen or respiratory support. Lastly, administering oxytocin to strengthen contractions for a quicker delivery (D) would not be appropriate in this case because the goal is to stop preterm labor rather than speed up delivery.