An infant has a loud, harsh, holosystolic murmur and systolic thrill that can be detected at the left lower sternal border that radiates to the neck. These clinical findings are consistent with which congenital heart defect?
a) atrial septal defect (ASD)
b) ventricular septal defect (VSD)
c) patent ductus arteriosus (PDA)
d) atrioventricular canal (AVC) defect