This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
Which one of the following drugs is used for fetal therapy of congenital adrenal hyperplasia? 
Select and explain. 
A. Hydrocortisone, B. Prednisolone, C. Fludrocortisone, D. Dexamethasone
D: Dexamethasone
Answer: D: Dexamethasone 
Explanation: Recommendations for pregnancy at risk consists of administration of dexamethasome a steroid that readily crosses the placenta'