**Core Concept**
Visceral pleura is a thin, double-layered membrane that covers the lungs, extending into the interlobar fissures and along the bronchi. It is a part of the pleural cavity, which is a space between the lungs and the chest wall. The visceral pleura is in direct contact with the lung parenchyma and follows the contours of the lungs.

**Why the Correct Answer is Right**
The visceral pleura is a highly vascularized layer that plays a crucial role in the process of respiration. It is composed of a single layer of flat, pleural mesothelial cells that secrete a thin layer of fluid, known as pleural fluid, which reduces friction between the lungs and the chest wall during breathing movements. The visceral pleura also contains blood vessels, lymphatic vessels, and nerves that supply the lungs.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect, as the visceral pleura does indeed cover the lungs and extends into the interlobar fissures.
**Option B:** Incorrect, as the visceral pleura is not a thick, fibrous layer but rather a thin, double-layered membrane.
**Option C:** Incorrect, as the visceral pleura is in direct contact with the lung parenchyma and is not a separate entity from the lung tissue.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the visceral pleura is a highly vascularized layer that can be involved in various respiratory conditions, such as pleural effusions and pneumothorax. Understanding the anatomy and physiology of the visceral pleura is crucial for diagnosing and managing these conditions.

**Correct Answer: A.**