Which drink is primarily filled with cranberry juice?

The drink primarily filled with cranberry juice is the Long Beach. This cocktail typically consists of vodka, triple sec, gin, rum, and cranberry juice, which is the primary mixer. The cranberry juice not only adds flavor but also gives the drink its characteristic reddish color.

In contrast, the Sloe Gin Fizz is a drink made with sloe gin, lemon juice, and soda water, thus not primarily based on cranberry juice. Similarly, the Blue Motorcycle incorporates blue curaçao, vodka, gin, rum, and sweet and sour mix, and does not revolve around cranberry juice. The Long Island Iced Tea, often known for its mix of various spirits such as vodka, gin, rum, tequila, and triple sec along with a splash of cola, also does not prominently feature cranberry juice. This detail highlights why the Long Beach stands out as the correct answer for the drink that primarily contains cranberry juice.