Final answer:
A patent ductus arteriosus, which occurs when the ductus arteriosus fails to close after birth, is a connection between the pulmonary artery and the aorta.
Step-by-step explanation:
A patent ductus arteriosus occurs when the ductus arteriosus fails to close after birth, which is a connection between the pulmonary artery and the aorta. The correct answer is c) Ductus arteriosus; pulmonary artery and aorta. When a patent ductus arteriosus occurs, it allows blood to flow from the higher-pressure aorta into the lower-pressure pulmonary artery. This can result in increased pulmonary pressure and difficulty in respiration, along with other symptoms such as shortness of breath, tachycardia, and poor weight gain in infants. Treatments range from nonsteroidal anti-inflammatory drugs to surgical interventions.