<prompt> Which of the following is a stimulus for closure of ductus arteriosus?Increased O2 tensionHypoxiaPrematurityHypercapnia  <response>: a. Increased O2 tensionRef: Nelsons 20e p 2162In the course of several days after birth, the high arterial Po2 constricts and eventually closes the ductus arteriosus, which eventually becomes the ligamentum arteriosum 