Select the option that can be used as a one-word substitute for the given group of words.
"Widespread occurrence of an infectious disease crossing international boundaries."

* Pandemic is an outbreak of a disease that occurs over a wide geographic area (such as multiple countries or continents) and typically affects a significant proportion of the population.
Epidemic is a widespread occurrence of an infectious disease in a community or region at a particular time (but limited in geographical scope compared to a pandemic).

Sporadic means occurring at irregular intervals or only in a few places.

Catastrophic means involving or causing sudden great damage or suffering.