Which component is common in both Hot Vanilla Mocha and Hot Caramel Mocha?

Both the Hot Vanilla Mocha and the Hot Caramel Mocha contain espresso as a fundamental component. Espresso is the base for both beverages, providing the rich coffee flavor that defines mochas. It contributes to the overall balance of sweetness and creaminess that is characteristic in both drinks, complementing the added flavors of vanilla and caramel.

The other choices, while they may be associated with various coffee drinks, are not common to both. For instance, white chocolate and coconut syrup are typically used in specific specialty drinks rather than being staples across mochas. Chocolate milk, while it can be a part of some chocolate-based drinks, is not generally a common ingredient in traditional mochas, as they rely on melted chocolate or cocoa mixed with espresso instead of chocolate milk. Thus, espresso serves as the unifying ingredient that ties the two drinks together.