What is the definition of a pandemic?

A pandemic is defined as a disease that is prevalent over a whole country or the world. This definition highlights the widespread nature of a pandemic, indicating that it affects a large geographic area and significant portions of the population, regardless of national borders.

In contrast, local or community-specific diseases refer to conditions that do not extend beyond a particular region or demographic. For instance, a locally prevalent disease is confined to a specific area and does not achieve the extensive reach and impact characteristic of a pandemic. Diseases affecting specific communities or those that are highly contagious but restricted to a single area also fall outside the definition of a pandemic, as they do not encompass the larger, global spread that defines this term.

Therefore, the choice that correctly captures the essence of a pandemic reflects its broad impact and widespread occurrence.