Final answer:
A woman with twins is at a higher risk for preeclampsia due to increased placental mass and metabolic demands, a common complication in multiple pregnancies.
Step-by-step explanation:
A woman who is pregnant with twins is at risk for several conditions, but in relation to the options provided, preeclampsia (B) is a common complication associated with twin pregnancies. Preeclampsia is a condition characterized by high blood pressure and often a significant amount of protein in the urine. Pregnant women with twins have a higher risk of preeclampsia because of the increased placental mass and its metabolic demands. Other possible complications associated with twin pregnancies include polyhydramnios or too much amniotic fluid, which can lead to premature labor or other pregnancy complications, and preterm labor is more common in multiple pregnancies. However, oligohydramnios (A), post-term labor (C), and chorioamnionitis (D) are not specifically associated with twin pregnancies in comparison to preeclampsia.