**Core Concept**
The Periodontal Disease Index is a method used to assess and score the severity of periodontal disease, which affects the gums and bone supporting the teeth. This index evaluates the **gingival and periodontal** components, focusing on signs of inflammation and loss of attachment. The scoring is based on clinical observations of **gingivitis** and **periodontitis**.

**Why the Correct Answer is Right**
Given the lack of specific details about the tooth's condition, a general understanding of the Periodontal Disease Index is necessary. The index typically scores teeth based on the presence and severity of **gingival inflammation**, **probing depth**, and **attachment loss**. Without specific information on these parameters, it's challenging to determine the exact score, but the process involves evaluating these key factors to assign a score that reflects the disease's severity.

**Why Each Wrong Option is Incorrect**
**Option A:** This option would be incorrect without evidence of severe disease.
**Option B:** Similarly, this option lacks justification without specific clinical findings.
**Option D:** This option is also incorrect as it does not align with the typical scoring system without further context.

**Clinical Pearl / High-Yield Fact**
The Periodontal Disease Index is crucial for diagnosing and monitoring periodontal disease progression. It helps in planning treatment and evaluating the response to therapy, emphasizing the importance of regular dental check-ups for **early detection of gingivitis** and **periodontitis**.

**Correct Answer:** Correct Answer: C. 8