Buying a Movie

In the Apple iTunes store, the movie "Dora and the Lost City of Gold" sells for $15, with no indication about the resolution quality. In the Google Play store, the same movie sells for $15 for HD resolution, and $20 for 4K resolution. So, does this mean that the 4K version is not available in the Apple iTunes store? Or, does this mean that the Apple iTunes store is selling the 4K version at a lower price than the Google Play store?

https://itunes.apple.com/us/movie/dora-and-the-lost-city-of-gold/id1473393537

https://play.google.com/store/movies/details/Dora_And_The_Lost_City_Of_Gold?id=MvzoKxmJXNQ.P