**Core Concept**
Mosquito-borne diseases are transmitted through the bite of infected female mosquitoes, which act as vectors. These diseases are typically caused by viruses, bacteria, or parasites that are ingested by the mosquito while feeding on the blood of an infected host. The mosquito then transmits the pathogen to a new host through its saliva.

**Why the Correct Answer is Right**
Plague, caused by *Yersinia pestis*, is primarily transmitted through the bites of infected fleas or direct contact with infected animals, not through mosquito bites. The plague can manifest in three forms: bubonic, pneumonic, and septicemic. While the bubonic form is typically transmitted through the bites of infected fleas, the pneumonic form can be transmitted between humans through respiratory droplets. The septicemic form is characterized by the presence of the bacterium in the bloodstream, often resulting from a primary bubonic infection.

**Why Each Wrong Option is Incorrect**
**Option A:** Japanese encephalitis is a viral disease transmitted by mosquitoes, specifically those of the *Culex* genus. It is a significant public health concern in many parts of Asia.
**Option B:** Dengue fever is another mosquito-borne disease, caused by the dengue virus, which is transmitted by *Aedes* mosquitoes. The disease is prevalent in tropical and subtropical regions worldwide.
**Option C:** Yellow fever is a viral disease transmitted by infected *Aedes* mosquitoes, primarily found in sub-Saharan Africa and South America. It is a major public health concern in these regions.

**Clinical Pearl / High-Yield Fact**
Mosquito-borne diseases can be prevented through the use of insecticide-treated bed nets, wearing protective clothing, and applying insect repellents. Additionally, eliminating breeding sites for mosquitoes, such as standing water, can help reduce the incidence of these diseases.

**✓ Correct Answer:** D. Plague