A. A primiparous patient who delivered a 7-pound 10-ounce baby 24 hours ago is at lower risk because primiparous patients generally have a lower risk of postpartum hemorrhage, and moderate birth weight babies rarely cause excessive uterine stretching. The 24-hour postpartum period also allows for initial uterine contraction. B. A multiparous patient who delivered a 9-pound baby 4 hours ago is correct because multiparity and macrosomia (large baby) increase the risk of uterine atony, which is the leading cause of postpartum hemorrhage. The patient is also in the early postpartum period (first 24 hours), which is when most hemorrhages occur, making this patient the highest risk. C. A primiparous patient who delivered a late preterm baby 24 hours ago is lower risk because smaller birth weight and primiparity reduce the risk of excessive uterine stretching and atony. D. A multiparous patient who delivered a 7-pound baby 6 hours ago is at some risk due to multiparity, but the smaller baby size reduces the likelihood of uterine atony compared with a 9-pound infant.