A 6-month-old male infant is brought to the ER after the sudden development of abdominal pain, irritability, and vomiting followed by passing of “currant jelly” stool. Ultrasound reveals intestinal obstruction in which the ileum collapsed through the ileocecal valve and invaginated into the large intestine. This type of obstruction is referred to as:
a. Prolapse
b. Pyloric stenosis
c. Intussusception
d. Imperforation