how would a government legally take control of another territory to add it to its own?\nannex it.\nappend…

Brief Explanations:

In international law and political - related contexts, "annex" refers to a government taking control of another territory to add it to its own. The other terms have different meanings in legal and general language usage and are not the correct terms for this specific action. "Append" usually means to add something at the end, "incorporate" can mean to include something into a larger whole in a more general sense, and "appropriate" often means to take something for one's own use, not specifically in the context of territorial acquisition.

Answer:

A. Annex it.