**Core Concept**
The staphylococcal capsule, also known as the polysaccharide capsule, is a complex structure formed by certain strains of Staphylococcus aureus. It plays a crucial role in the pathogenesis of the bacterium, particularly in its ability to evade the host's immune system. The capsule is composed of a specific polysaccharide material that surrounds the bacterial cell wall.

**Why the Correct Answer is Right**
The staphylococcal capsule is primarily made up of a polysaccharide material known as teichoic acid, which is embedded in the cell wall of the bacterium. This unique structure allows the bacterium to resist phagocytosis and evade the host's immune response. The capsule is also responsible for the bacterium's ability to cause severe infections, particularly in individuals with compromised immune systems.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not accurately describe the composition of the staphylococcal capsule. While lipoteichoic acid is a component of the cell wall, it is not the primary material that makes up the capsule.
* **Option B:** This option is incorrect because it is a component of the bacterial cell wall, but not the primary material that makes up the capsule.
* **Option D:** This option is incorrect because it is not a known component of the staphylococcal capsule.

**Clinical Pearl / High-Yield Fact**
The staphylococcal capsule is an important virulence factor that contributes to the bacterium's ability to cause severe infections. Understanding the composition and function of the capsule is crucial for the development of effective treatments and vaccines.

**Correct Answer:** A. Teichoic acid.