## **Core Concept**
The placenta plays a crucial role in fetal development during intrauterine life, providing oxygen, nutrients, and removing waste products. However, some organs or systems in the fetus develop and function independently of the placenta.

## **Why the Correct Answer is Right**
The correct answer, **D. Lung**, is right because, unlike other organs that rely on the placenta for their development and function, the lungs start developing and have a critical role in gas exchange (oxygen and carbon dioxide) even before birth, although the gas exchange primarily occurs through the placenta. The lungs begin to practice breathing movements in utero, which is essential for their maturation. This intrinsic development and function make the lungs less dependent on the placenta compared to other organs like the liver or pancreas, which are primarily sustained by the placenta during fetal development.

## **Why Each Wrong Option is Incorrect**
- **Option A:** The liver's development and function are significantly influenced by the placenta. It receives blood from the umbilical vein and processes nutrients.
- **Option B:** The pancreas develops under the influence of various factors, and its function, especially in terms of glucose regulation, is affected by the intrauterine environment provided by the placenta.
- **Option C:** The gut (or intestines) relies on the placenta for nutrients; its development includes practicing peristalsis and absorption functions in utero.

## **Clinical Pearl / High-Yield Fact**
A critical point to remember is that while the placenta supports the fetus's overall growth, organs like the lungs start practicing essential functions before birth. This is why prematurity can lead to respiratory distress syndrome due to immature lung function.

## **Correct Answer:** D. Lung