**Core Concept**
The poliovirus is a highly infectious **RNA virus** belonging to the **Picornaviridae** family, primarily affecting the **central nervous system**. It spreads through the **fecal-oral route**. Understanding its transmission, pathogenesis, and clinical manifestations is crucial for its management and prevention.

**Why the Correct Answer is Right**
Without the specific options provided, a general overview of poliovirus characteristics is necessary. Typically, true statements about poliovirus include its high infectivity, the role of **vaccine-induced immunity** in its control, and the potential for **paralytic poliomyelitis** in severe cases. The correct answer would contradict a known fact about poliovirus, such as its transmission, symptoms, or prevention methods.

**Why Each Wrong Option is Incorrect**
**Option A:** Would be incorrect if it stated something untrue about poliovirus, such as it being a DNA virus.
**Option B:** Might claim poliovirus is primarily spread through vectors, which is incorrect as it mainly spreads through the fecal-oral route.
**Option C:** Could inaccurately describe the virus's target in the human body, such as saying it only affects the peripheral nervous system.
**Option D:** Might falsely state that there is no vaccine available for poliovirus, which is incorrect given the existence of **OPV (Oral Poliovirus Vaccine)** and **IPV (Inactivated Poliovirus Vaccine)**.

**Clinical Pearl / High-Yield Fact**
A crucial point to remember is that **immunization** is key to preventing polio, with both OPV and IPV being effective tools in global eradication efforts. Understanding the differences between these vaccines, including their administration routes and immunity durations, is vital for public health strategies.

**Correct Answer:** D. Polio is a DNA virus.