What is squeezed and dropped over the ice in both the Caribbean Luxe and Long Island Tea recipes?

The correct answer is lemon, as both the Caribbean Luxe and Long Island Tea recipes commonly incorporate freshly squeezed lemon juice. This ingredient adds a zesty and tart flavor, which is essential for balancing the sweetness from the spirits and mixers used in these cocktails.

In cocktail preparation, the freshness of lemon juice enhances the overall taste profile, making it a popular choice in many drink recipes. The sharpness of lemon complements various spirits while providing a refreshing contrast to the other ingredients. This is why it's squeezed and added over the ice in these particular drinks, allowing the citrus notes to meld with the other flavors effectively.

Other options like lime, orange, and grapefruit may be commonly used in various cocktails but are not the primary citrus specified for these two drinks. While lime is prevalent in many tropical cocktails and orange juice often finds its place in mixed drinks, neither is used in the same manner or quantity as lemon in the mentioned recipes. Hence, lemon is the key ingredient that directly ties to the preparation of both the Caribbean Luxe and Long Island Tea.