Columbus Day has been an official U.S. holiday since 1937. But some people question celebrating Christopher Columbus’s arrival in the “New World.”

That’s because of what followed that “discovery.” News of Columbus’s voyages spread across Europe. It began the Age of Exploration. It led to many more transatlantic journeys from Europe to the Americas. Contact between the Europeans and and native people led to deadly conflicts. It also exposed the local inhabitants to European diseases. Native people had no natural immunity to those illnesses. Nor did they understand how the diseases traveled. Their efforts to flee from places filled with dying people ended up spreading the diseases.

Which reason does the author use to support the point that celebrating Columbus Day is questionable because of the events that followed Columbus’s arrival?