A nurse is admitting a client who is at 30 weeks of gestation and is in preterm labor. The client has a new prescription for betamethasone and asks the nurse about the purpose of this medication. The nurse should provide which of the following explanations?

A. "It halts cervical dilation." This is incorrect because betamethasone does not stop cervical dilation or preterm labor. Medications like tocolytics (e.g., nifedipine, magnesium sulfate, terbutaline) are used to delay labor, while betamethasone is given to enhance fetal lung maturity. B. "It increases the fetal heart rate." This is incorrect because betamethasone does not directly increase fetal heart rate. While corticosteroids may cause temporary fetal tachycardia, their primary role is enhancing fetal lung development. C. "It promotes fetal lung maturity." This is correct because betamethasone is a corticosteroid given to promote the production of surfactant in the fetal lungs, reducing the risk of respiratory distress syndrome (RDS) in preterm infants. It is typically administered between 24 and 34 weeks of gestation in cases of anticipated preterm birth. D. "It is used to stop preterm labor contractions." This is incorrect because betamethasone does not stop contractions. Tocolytics like nifedipine, magnesium sulfate, and terbutaline are used for that purpose, whereas betamethasone is specifically for fetal lung development.