**Core Concept**
The question pertains to the classification of microorganisms based on their cell wall structure. Bacterial cell walls can be broadly categorized into two types: Gram-positive and Gram-negative, based on the Gram staining technique. However, the question specifically asks about capsulated organisms.

**Why the Correct Answer is Right**
Capsulated organisms, also known as encapsulated bacteria, are those that have a polysaccharide capsule surrounding their cell wall. This capsule provides protection against phagocytosis and desiccation. The mechanism behind this protection involves the capsule's ability to prevent the binding of complement proteins and neutrophils, thereby evading the host's immune response. The presence of a capsule is a key virulence factor in many pathogenic bacteria.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incomplete and does not provide a valid answer choice.

**Option B:** This option is incorrect because it does not directly relate to the concept of capsulated organisms. While it may be a characteristic of some bacteria, it is not a defining feature of capsulated organisms.

**Option C:** This option is incorrect because it is a type of bacterial cell wall structure, but not a characteristic of capsulated organisms.

**Clinical Pearl / High-Yield Fact**
It is essential to note that the presence of a capsule is a key virulence factor in many pathogenic bacteria, including *Streptococcus pneumoniae*, *Haemophilus influenzae*, and *Neisseria meningitidis*. A capsule is often associated with invasive disease and can be a target for vaccine development.

**Correct Answer:** D. Capsulated organisms typically include bacteria with a polysaccharide capsule surrounding their cell wall, such as *Streptococcus pneumoniae*.