The word that best completes the sentence is "congregated."
In this context, "congregated" implies people gathering or assembling together, which fits the scenario of individuals waiting outside the church for the bride and groom.
The other options, "classified," "persuaded," and "ejected," do not convey the idea of people gathering in a specific location.
"Classified" refers to categorization, "persuaded" involves influencing someone's beliefs or actions, and "ejected" implies expulsion or removal, none of which capture the sense of people gathering outside the church.
Therefore, the most suitable choice is "congregated."