Read the following text and answer the following question on the basis of the same:
Shivani studies in class I. Her parents come from a backward family and are unaware of immunization programme. So, she did not get vaccinated properly. Once playing with her friends in the park, she fell down due to weakness and later complained of high fever, head ache and stiffness in her neck.
The microbe responsible for Shivani's illness may be:

Options

A. Vibrio cholerae
B. Enterovirus
C. Plasmodium
D. Mycobacterium

Explanation

To determine the microbe responsible for Shivani's illness based on the provided text, we can follow these steps:

### Step-by-Step Solution:

1. **Identify Symptoms**: The text mentions that Shivani experienced high fever, headache, and stiffness in her neck. These symptoms are crucial for identifying the potential illness.

2. **Consider the Context**: Shivani did not receive proper vaccinations due to her parents' lack of awareness about immunization programs. This suggests that she may be susceptible to diseases that vaccines typically prevent.

3. **Focus on Neck Stiffness**: Among the symptoms, neck stiffness is particularly significant. It is often associated with meningitis, which can be caused by various pathogens, including viruses.

4. **Evaluate Possible Microbes**:
- **Polio Virus**: The text suggests that Shivani may have been exposed to the polio virus, especially since she was playing in a park and had not been vaccinated. The polio virus can cause neurological symptoms, including neck stiffness.
- **Vibrio cholera**: This bacterium causes cholera, which is characterized by severe diarrhea and dehydration, not neck stiffness.
- **Enterovirus**: This is a broader category that includes the polio virus. It can cause various illnesses, but the specific symptoms here point more towards polio.
- **Plasmodium**: This protozoan causes malaria, which is associated with fever and chills, but not neck stiffness.
- **Mycobacterium**: This bacterium causes tuberculosis, which primarily affects the lungs and does not typically present with neck stiffness.

5. **Conclusion**: Given the symptoms and the context of lack of vaccination, the most likely microbe responsible for Shivani's illness is the **Polio Virus**.

### Final Answer:
The microbe responsible for Shivani's illness may be the **Polio Virus**.

---