**Core Concept:** Negative sense RNA viruses are a group of viruses that have the unique property of encoding their genetic material using a strand of RNA that is opposite in sequence to the mRNA being transcribed from it. This means that the RNA strand used for protein synthesis is the complementary (not the original) RNA strand.

**Why the Correct Answer is Right:** The correct answer, Dengue virus, is a member of the Flaviviridae family, which is known to have negative sense RNA. During replication, the negative sense RNA strand serves as a template for synthesizing a positive sense RNA strand, which is then used for protein synthesis. This is in contrast to most RNA viruses that use a positive sense RNA strand as the template for protein synthesis.

**Why Each Wrong Option is Incorrect:**

A. Hepatitis C virus (HCV) is a positive sense RNA virus, meaning it uses a positive sense RNA strand as its template for protein synthesis.

B. Influenza virus is a positive sense RNA virus, similar to HCV, but with a different mechanism of replication.

C. Herpes simplex virus (HSV) is a DNA virus and does not have negative sense RNA.

**Clinical Pearl / High-Yield Fact:** Understanding the different types of RNA viruses (positive sense, negative sense, and ambisense) and their replication mechanisms is crucial for understanding viral pathogenesis and antiviral therapy strategies. Negative sense RNA viruses, like Dengue, can cause severe hemorrhagic fever and have been linked to thrombocytopenia and platelet dysfunction.

**Correct Answer:** Dengue virus (Flaviviridae family) has negative sense RNA.