This episode is significant for several reasons:
* It marked the series finale: It was the final episode of the show, which garnered a large viewership for its closure.
* High stakes and emotional climax: It featured a critical choice for Alex, and it delivered a satisfying resolution to the main character arc.
* Strong marketing: The episode was heavily promoted by Disney, generating further hype and anticipation.
While this is the most commonly cited as the most watched, it's impossible to confirm definitively without official viewership data. However, the combination of its importance to the series, emotional weight, and marketing efforts makes it a very likely candidate for the most watched episode.