How can you integrate content cards on Android?

Integrating content cards on Android using a fragment is the correct approach because fragments provide a modular section of an activity that can be added or removed while the activity is running, which is particularly useful for reusable UI components like content cards. This allows developers to create a more dynamic and user-friendly experience by managing the lifecycle of the content cards more effectively within the context of the host activity.

A fragment can host various UI elements and manage their interactions seamlessly. Since content cards are often designed to be displayed as part of a flexible UI that should adapt based on the activity's state or the user's actions, fragments are the ideal component to implement this feature.

In contrast, using an activity alone would imply that the content cards are tightly coupled to a specific screen, which limits reusability and flexibility. A service operates in the background and does not provide a user interface, making it unsuitable for displaying content cards. Similarly, a broadcast receiver is designed to respond to system-wide broadcast announcements and is not intended for managing user interface elements like content cards. Thus, using a fragment allows for a clean and manageable integration of content cards in an Android application.