**Core Concept**
Mumps is a viral infection caused by the mumps virus, a member of the paramyxovirus family. It primarily affects the salivary glands near the ears, leading to symptoms such as swelling, fever, and headache.

**Why the Correct Answer is Right**
The incubation period of mumps is typically 16 to 18 days, with a range of 12 to 25 days. This prolonged incubation period is essential for clinicians to recognize the disease, as symptoms may not appear immediately after exposure. The delayed onset of symptoms is due to the virus's replication and dissemination within the body. In contrast, other viral infections like measles and rubella have shorter incubation periods.

**Why Each Wrong Option is Incorrect**
**Option A:** Mumps is indeed caused by a paramyxovirus, specifically the mumps virus. This statement is accurate and not a feature of mumps that the question is asking to exclude.
**Option B:** Aseptic meningitis is a recognized complication of mumps, particularly in children. This statement is true and does not match the answer choice.
**Option C:** Orchitis, or inflammation of the testes, is a complication of mumps in post-pubescent males. This statement is accurate and does not fit the answer choice.

**Clinical Pearl / High-Yield Fact**
Mumps is a vaccine-preventable disease. The mumps vaccine is often administered in combination with vaccines for measles and rubella (MMR vaccine) and is recommended for all children to prevent the spread of the disease.

**Correct Answer:**
✓ Correct Answer: D. Incubation period is less than 2 weeks.