**Core Concept**
Arboviral diseases are a group of illnesses caused by viruses transmitted primarily through the bites of infected arthropods such as mosquitoes and ticks. These viruses replicate within the insect vector before being transmitted to humans or other animals, leading to a range of clinical manifestations.

**Why the Correct Answer is Right**
The correct answer is related to the fact that arboviral diseases often present with a triad of symptoms: fever, rash, and arthritis. This is a result of the virus targeting and infecting cells in the skin, joints, and other tissues. For example, in the case of dengue fever, the virus replicates in the skin and lymphoid tissues, leading to the characteristic rash and joint pain.

**Why Each Wrong Option is Incorrect**
**Option A:** Arboviral diseases are primarily transmitted through direct contact with infected animals. This is incorrect because while some arboviruses can be transmitted through contact with infected animals, the primary mode of transmission is through the bite of an infected arthropod.
**Option B:** Arboviral diseases are always severe and life-threatening. This is incorrect because while some arboviruses can cause severe illness, others may present with mild symptoms or be asymptomatic.
**Option C:** Arboviral diseases are only found in tropical regions. This is incorrect because while some arboviruses are more commonly found in tropical regions, others can be found in temperate and subtropical regions as well.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the presence of a rash in a patient with fever and joint pain should raise suspicion for an arboviral disease, particularly in endemic areas. A thorough travel and exposure history is crucial in making an accurate diagnosis.

**Correct Answer:** C.