Read the passage about what happened in Pompeii after Mount Vesuvius erupted.

There was found a skeleton with a bronze axe, having attempted to break through the wall next to him. It is not unreasonable to suppose that he was . . . unable to flee by means of the courtyard, where the volcanic debris was too abundant, had attempted to make his way through the opposite wall.

–François de Paule Latapie

Why is the passage an example of a secondary source?

The author is describing a firsthand account of the ruins of Pompeii.
The author is providing commentary on his discovery in the ruins of Pompeii.
The author is explaining what he experienced during the eruption of Mount Vesuvius.
The author is presenting evidence about the damage caused by the eruption of Mount Vesuvius.