5. Why it was called pandemic COVID-19? *
A. It was called pandemic COVID-19 because it started at 2019.
B. It was called pandemic COVID-19 because it came from Wuhan, China.
C. It was called pandemic COVID-19 because it is a new strain of virus.
D. It was called pandemic COVID-19 because it is an infectious disease that spread in more than 100 countries.