Read the passage. In this year came dreadful forewarnings over the land of Northumbria, terrifying the people most woefully: these were immense sheets of lightning and whirlwinds, and fiery dragons were seen flying through the sky. . . . And not long after . . . the harrowing inroads of heathen men destroyed the church of God in Lindisfarne.

–The Anglo-Saxon Chronicle, 800 CE

What is the central idea of the passage?

Dragons attacked Northumbria.
Northumbria was attacked by wind.
Sheets of lightning terrified the Northumbrian people.
The people of Northumbria were terrified by the heathen men who are invading.