Question

In the _____ to the coast of Mexico.

following year, Cortes had to return
following year Cortes had to return,
following, year Cortes had to, return
following, year Cortes had to return

Answer 1

following year, Cortes had to return
This would be the way to write it out, this is because a comma is more or less like a pause button, in which you would take a breath and continue reading or speaking. Lets face it, no one starts speaking and doesn't stop until they run out of breath.

Answer 2

The first one is the answer