## Core Concept
Umbilical hernias are protrusions of intestinal or omental contents through a defect in the abdominal wall at the umbilicus. They are common in infants but can also occur in adults, often due to increased intra-abdominal pressure or weakness in the abdominal wall.

## Why the Correct Answer is Right
The correct answer, although not directly provided, relates to the characteristics or management of umbilical hernias. Typically, umbilical hernias in adults are more likely to incarcerate or strangulate compared to those in children. Surgical repair is often recommended for adults due to the higher risk of complications.

## Why Each Wrong Option is Incorrect
- **Option A:** Without specific details on option A, it's challenging to provide a direct explanation. However, if option A states that umbilical hernias are more common in adults, this would be incorrect as they are more common in children.
- **Option B:** Similarly, without specifics, if option B mentions a characteristic or treatment approach that is generally accepted for umbilical hernias (like surgical repair for adults), it would be correct and not the answer we're looking for.
- **Option C:** This option's accuracy depends on its content. If it suggests that most umbilical hernias in children close spontaneously, this is correct and not the "except" part we're looking for.
- **Option D:** If option D provides an incorrect statement regarding umbilical hernias, such as suggesting they are typically managed conservatively in adults, this could be the incorrect statement.

## Clinical Pearl / High-Yield Fact
A key point to remember is that while umbilical hernias in children often close spontaneously by the age of 5, those occurring in adults are more likely to require surgical intervention due to the increased risk of incarceration and strangulation.

## Correct Answer: D.