A 1-day-old infant has a mass protruding through her umbilicus. Physical examination reveals an umbilical hernia. A CT scan reveals that part of another organ is attached to the inner surface of the hernia. What portion of the gastrointestinal tract is most likely to be attached to the inner surface of the umbilical hernia?

The ileum is the best answer choice here because it is the most common site of Meckel diverticulum. This outpouching is a persistence of the vitelline duct and it can be attached to the umbilicus. The other answer choices are not correlated with the vitelline duct and therefore will not result in the condition discussed here.