**Core Concept**
Monkey disease, also known as Lassa fever, is a viral hemorrhagic fever caused by the Lassa virus. It is a zoonotic disease, primarily transmitted to humans through contact with infected rodents or their droppings.

**Why the Correct Answer is Right**
Lassa fever is endemic in West Africa, particularly in countries such as Nigeria, Liberia, and Sierra Leone. The virus is transmitted to humans through inhalation of aerosolized virus particles from infected rodents, or through direct contact with infected rodents or their droppings. The virus then replicates in the host cells, leading to a range of symptoms including fever, headache, and hemorrhaging.

**Why Each Wrong Option is Incorrect**
**Option A:** Ebola is a different viral hemorrhagic fever, caused by the Ebola virus, and is not commonly referred to as Monkey disease.
**Option B:** Marburg virus disease is another viral hemorrhagic fever, caused by the Marburg virus, and is not known as Monkey disease.
**Option C:** Monkeypox is a viral disease caused by the Monkeypox virus, and is characterized by a rash and fever, but is not referred to as Monkey disease.

**Clinical Pearl / High-Yield Fact**
Lassa fever is often misdiagnosed as malaria or typhoid fever, highlighting the importance of considering the patient's travel history and exposure to rodents when diagnosing febrile illnesses.

**Correct Answer:** C. Monkeypox