system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Which of the following is a stimulus for closure of ductus arteriosus?
assistant
The correct answer is  a. Increased O2 tension(Ref: Nelson's 20/e p 2162)In the course of several days after birth, the high arterial Po2 constricts and eventually closes the ductus arteriosus, which eventually becomes the ligamentum arteriosum