Why Was the Lethal Strain of Influenza That Killed Over

Why was the lethal strain of influenza that killed over 30 million people worldwide during the pandemic of 1918-1919 called Spanish Influenza?

A) The virus originated as a mutated version of avian flu in Spain.
B) The outbreak of this disease was first reported by a Spanish newspaper.
C) Spanish travelers and immigrants coming to the United States introduced it to urban areas.
D) The pandemic had its origins in Spain's former Caribbean colonies of Cuba and Puerto Rico.