## Core Concept
The treatment of oral tongue carcinoma, like other cancers, is primarily guided by the tumor's stage, which is determined by the TNM system (Tumor size, Node involvement, Metastasis). Stage III carcinoma of the oral tongue typically indicates a larger tumor size (T3) or the presence of lymph node metastasis (N1) with no distant metastasis (M0). The management of oral cancer involves surgery, radiotherapy, and sometimes chemotherapy, depending on the stage and location of the tumor.

## Why the Correct Answer is Right
For stage III carcinoma of the oral tongue, the standard treatment often involves a combination of surgery and radiotherapy. Surgery is usually the primary treatment to remove the tumor and involved lymph nodes. This may be followed by radiotherapy (adjuvant therapy) to eliminate any remaining cancer cells, especially if the surgical margins are close or if there are adverse features like lymphovascular invasion. The goal is to achieve local control of the disease and improve survival.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is incorrect because it does not specify a treatment approach commonly used for stage III oral tongue cancer. Without details, it's hard to judge, but typically, treatment for stage III disease involves more than just one modality.
- **Option B:** This option might suggest a treatment that is not comprehensive enough for stage III disease. For instance, if it suggests only surgery or only radiotherapy, it might not adequately address the potential microscopic disease spread.
- **Option C:** This could imply chemotherapy alone, which is not the standard primary treatment for localized or locally advanced oral cancer like stage III carcinoma of the oral tongue. Chemotherapy might be used in conjunction with radiotherapy (chemoradiation) in certain cases or for palliation in advanced disease.

## Clinical Pearl / High-Yield Fact
A key point to remember is that for oral cancers, especially those that are locally advanced like stage III, multidisciplinary treatment planning is crucial. Surgery is often the mainstay of treatment, but adjuvant radiotherapy (and sometimes chemotherapy) can significantly impact outcomes. Always consider the potential need for comprehensive treatment planning, including rehabilitation and supportive care, in the management of oral cancer patients.

## Correct Answer Line
**Correct Answer: D.**