It seems like you're referring to an interactive quiz or questionnaire with a drop-down menu option for completing the sentence. Since I don't have access to interactive features or menus, I can suggest an answer based on historical context.
For the sentence "Axum’s adoption of Christianity shows its connection to," a suitable completion could be "the Roman Empire" or "trade networks with the Mediterranean world."
If you need a specific answer for a drop-down menu, please provide the options available, and I'd be happy to help you select the most appropriate one!