Read the passage

I say, then, that the years [of the era] of the fruitful Incarnation of the Son of God had attained to the number of one thousand three hundred and forty-eight, when into the notable city of Florence, fair over every other of Italy, there came the death-dealing pestilence, which, through the operation of the heavenly bodies or of our own iniquitous dealings, being sent down upon mankind for our correction by the just wrath of God, had some years before appeared in the parts of the East and after having bereft these latter of an innumerable number of inhabitants, extending without cease from one place to another, had now unhappily spread towards the West.

–Letter to the king of England,
Joan of Arc, 1492

What is Boccaccio’s main purpose in the passage?

to scare the reader about the disease
to inform the reader about the disease
to persuade the reader to agree with his views
to entertain the reader by telling a historical tale