<prompt>  A 4-month old infant is brought to the physician for a routine examination. Physical examination shows epicanthic folds and a palmar simian crease. Cytogenetic testing shows an autosomal trisomy. Which of the following cardiac anomalies is most commonly associated with this condition?Atrial septal defectComplete Atrioventricularseptal defectMitral stenosisPatent ductusarteriosus 