**Core Concept**
The condition described is likely mumps, a viral infection caused by the mumps virus (MuV). Mumps is a contagious disease that primarily affects the salivary glands, leading to swelling in the face, particularly below the ears.

**Why the Correct Answer is Right**
Mumps immunization is achieved through the MMR (Measles, Mumps, and Rubella) vaccine. The MMR vaccine contains live, attenuated viruses that stimulate the body's immune system to produce antibodies against measles, mumps, and rubella. Upon exposure to the wild virus, the immune system can recognize and neutralize it, preventing the disease. The vaccine is administered in two doses: the first at 12-15 months of age and the second at 4-6 years of age.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not relevant to the question, as there is no well-known vaccine for the exact condition described.
* **Option B:** This option is incorrect, as the varicella vaccine protects against chickenpox, not mumps.
* **Option C:** This option is incorrect, as the Hib (Haemophilus influenzae type b) vaccine protects against bacterial meningitis, not mumps.
* **Option D:** This option is incorrect, as the HPV (Human Papillomavirus) vaccine protects against certain types of cancer and genital warts, not mumps.

**Clinical Pearl / High-Yield Fact**
Mumps is a vaccine-preventable disease, and its inclusion in the MMR vaccine has led to a significant decline in its incidence. However, the vaccine's effectiveness can wane over time, making booster shots essential for maintaining immunity.

**Correct Answer:** C. MMR (Measles, Mumps, and Rubella) vaccine.