**Core Concept**
The treatment of carcinoma cervix stage III B involves a combination of radiation therapy and chemotherapy to control the tumor and alleviate symptoms. This approach is based on the principle of concurrent chemoradiation, which aims to enhance the radiosensitivity of cancer cells and improve local control.

**Why the Correct Answer is Right**
The standard treatment for stage III B cervical cancer is concurrent chemoradiation, which typically consists of external beam radiation therapy (EBRT) and brachytherapy, combined with a platinum-based chemotherapy regimen, such as cisplatin. The combination of radiation and chemotherapy has been shown to improve survival rates and reduce the risk of recurrence compared to radiation therapy alone. The chemotherapy agent, cisplatin, works by inhibiting DNA repair mechanisms and inducing DNA damage in cancer cells, making them more susceptible to radiation.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the use of concurrent chemoradiation, which is the standard treatment for stage III B cervical cancer.
**Option B:** This option is incorrect because it suggests a treatment approach that is not evidence-based for stage III B cervical cancer.
**Option C:** This option is incorrect because it implies that surgery is the primary treatment for stage III B cervical cancer, which is not the case.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the treatment of cervical cancer is highly dependent on the stage and extent of disease, and a multidisciplinary approach involving radiation oncology, medical oncology, and gynecologic oncology is often required to achieve optimal outcomes.

**Correct Answer: C. Concurrent chemoradiation with cisplatin.**