Final answer:
The first symptom of chorioamnionitis in the postpartum period is a foul-smelling discharge (option d).
Step-by-step explanation:
The first symptom of chorioamnionitis in the postpartum period for a patient who had ruptured membranes for 72 hours before delivery is a foul-smelling discharge (option d). Chorioamnionitis is an infection of the fetal membranes and amniotic fluid typically caused by bacteria entering the uterus after the membranes have ruptured for an extended period. This infection can lead to complications for both the mother and the baby, so prompt medical attention is necessary.