Answer:
Explanation:
**D. All of the above are challenges.**
Each of the options listed represents a significant challenge to achieving universal immunization coverage:
- **Vaccine hesitancy** can lead to reduced vaccination rates as individuals or communities may refuse or delay vaccination despite availability.
- **Political conflicts and fragility of some states** can disrupt vaccination programs and prevent effective distribution and administration of vaccines.
- **Threats to global cooperation** can hinder collaborative efforts and resource sharing necessary for widespread immunization efforts.
Therefore, all of these factors contribute to the challenges faced in achieving universal immunization coverage.